photocopy only IT necess







hem .














Printed in Great Britain by Butler & Tanner. Frome and London.


A COMPARISON between the present work, the latest edition of the German original, and the last American translation, will show that while the German text-book has been faithfully followed, modifications have been introduced which will be regarded, it is hoped, in the light of solid improvement. Certain statements have been corrected or modified, changes which have usually been indicated, and a great number of minor alterations have been made in the marshalling of facts and the setting out of formulae with the object of a more logical sequence and a clearer emphasis of the point under discussion.

References to German literature have been retained with the object of preserving to the student the advantages of the origin of the book; the English references will be otherwise readily obtainable by him.

I take great pleasure in expressing my gratitude to Mr. W. P. Skertchly, F.I.C., not only for assistance in the more mechmical part of the translation, but also for the careful way in which he has read through the proofs.

Furthermore, to Mr. A. J. Greenaway, Sub-Editor of the Journal of the Chemical Society, I offer my most cordial thanks for his valued advice on certain doubtful points of nomenclature.


N.B. The Publishers beg to explain that a year's delay has occurred in the production of this volume (announced for the autumn of 1914), owing to Dr. Spielmann's employment on important work connected with explosives for the Government.

K. P. T. T. & Co., LTD.


NOTWITHSTANDING the depletion of students from the many Technical Institutions as a result of the late war, a second edition of the first volume of this text-book has been called for a gratifying recognition of its continued and increasing usefulness.

As inevitable to the first production of a book of this character, with its innumerable formulae and figures, a certain number of mis- prints had crept in, and a careful search for these has been made.

The need of such rectifications must not deter me from paying a tribute to the printers, Messrs. Clowes and Sons, for the care and success with which they have carried through so complicated a piece of type setting ; while to the Publishers is due acknowledgment for much that was of assistance in my share of the work of production.

It is believed that, in its revised form, this volume will be found to meet all the requirements of the daily expanding class of chemical students, on whose services will depend so important a share in the scientific foundation of the firm establishment and success of British Industry.




IN presenting this translation of the eighth German edition of v. Richter's " Organic Chemistry " the writer has little to add to what has previously been expressed in the prefaces to the preceding American editions of this most successful book. The student of the present edition will, however, very quickly discover that the subject-matter, so ably edited by Professor Anschiitz, is vastly different from that given in the earlier editions. Indeed, the book has sustained very radical changes in many particulars, and certainly to its decided advantage. The marvellous advances in the various lines of synthetic organic chemistry have made many of the changes in the text abso- lutely necessary, and for practical reasons it has seemed best to issue this new edition in two volumes.

Eminent authorities, such as Profs, v. Baeyer, E. Fischer, AVaitz, Claisen, and others, have given the editor the benefit of their super- vision of chapters relating to special fields of investigation in which they are the recognized authorities.

The translator here acknowledges his great indebtedness to his publishers, P. Blakiston's Son & Co., for their constant aid in his work, as well as to Messrs. Wm. F. Fell & Co., for the care they have taken and the skill they have displayed in the composition of what will generally be admitted to be a difficult piece of typography.




THE present American edition of v. Richter's " Organic Chemistry " will be found to differ very considerably, in its arrangement and size, from the first edition. The introduction contains new and valuable additions upon analysis, the determination of molecular weights, recent theories on chemical structure, electric conductivity, etc. The section devoted to the carbohydrates has been entirely rewritten, and presents the most recent views in regard to the constitution of


this interesting group of compounds. The sections relating to the trimethylene, tetramethylene, and pentamethylene series, the fur- furane, pyrrol, and thiophene derivatives, have been greatly enlarged, while the subsequent chapters, devoted to the discussion of the aromatic compounds, are quite exhaustive in their treatment of special and important groups. Such eminent authorities as Profs. Ostwald, von Baeyer, and Emil Fischer have kindly supervised the author's presentation of the material drawn from their special fields of investigation.

The characteristic features of the first edition have been retained, so that the work will continue to be available as a text-book for general class purposes, useful and reliable as a guide in the preparation of organic compounds, and well arranged and satisfactory as a refer- ence volume for the advanced student as well as for the practical chemist.

The translator would here express his sincere thanks to Prof. v. Richter, whose hearty co-operation has made it possible for him to issue this translation so soon after the appearance of the sixth German edition.



THE favourable reception of the American translation of Prof, von Richter's " Inorganic Chemistry " has led to this translation of the " Chemistry of the Compounds of Carbon/' by the same author. In it will be found an unusually large amount of material, necessitated by the rapid advances in this department of chemical science. The portions of the work which suffice for an outline of the science are presented in large type, while in the smaller print is given equally important matter for the advanced student. Frequent supplementary references are made to the various journals containing original articles, in which details in methods and fuller descriptions of properties, etc., may be found. The volume thus arranged will answer not only as a text -book, and indeed as a reference volume, but also as a guide in carrying out work in the organic laboratory. To this end numerous methods are given for the preparation of the most important and the most characteristic derivatives of the different classes of bodies.




A. chim. phys. Am. Anorg. Ch.

Arch. exp. Path. Arch. ges. Phys.


Bull. soc. chim.


Ch. Ztg.



A1, A2, A3, etc.

D. R. P.

Gaz. chim. ital. F.Hdw.

J. Chem. Soc.

J. pr. Ck., or J. pr. Ch.

N. F. ' . L.Hdw.

M. .... Pharm. Centr. Phil. Mag. . Pogg. A., or Wied. A.


R. Meyer's J. Wied. A. Wien. Monatsh. Z.

Z. anal. Ch. . Z. angeiv. Ch. Z. anorg. Ch. Z. Electroch. . Z. Kryst. Z.fhys. Ch. . Z. physiol. Ch.

Liebig's Annalen der Chemie. Spl. Supplementband.

Annales de chemie et de physique.

American Chemical Journal.

Richter-Klinger, Lehrbuch der anorganischen Chemie.

Richter-Smich, Text-book of Inorganic Chemistry.

Archiv fur experimentelle Pathologic und Pharmakologie.

Archiv fur die gesammte Physiologic.

Specific optical rotation.

Berichte der deatschen chemischen Gesellschaft.

R = Referate.

Boiling point. Bp10 = Boiling point at 10 mm. pressure of


Bulletin de la societe chimique de Paris. Chemisches Centralblatt. Chemiker-Zeitung.

Comptes rendus des stances de 1' Academic des science?. Density, specific gravity, D20= Sp. gr. at 20° C. Denotes the position of a double linkage in a carbon chain,

reckoned from the C-atom I, 2, 3, etc. to the next

higher member. Deutsches Reichspatent. Gazetta chimica italiana. Fehling's Hand wort erbuch fur Chemie. Jahresbericht fur die Fortschritte der Chemie. Journal of the Chemical Society.

Journal fur praktische Chemie. Neue Folge.

Ladenburg's Handworterbuch fur Chemie.

Monatshefte fiir Chemie.

Pharmaceutische Centralhalle.

Philosophical Magazine.

Annalen der Physik und Chemie, published by Poggendorf j

or new series, published by Wiedemann. See B.

Richard Meyer's Jahrbuch der Chemie. See Pogg. A.

Monatsheft fiir chemie (Vienna). Zeitschrift fur Chemie. Zeitschrift fiir analytische Chemie. Zeitschrift fiir angewandte Chemie. Zeitschrift fiir anorganische Chemie. Zeitschri^t fiir Electrochemie. Zeitschrift fiir Krystallographie und Mineralogie. Zeitschrift fiir physicalische Chemie. Hoppe-Seyler's Zeitschrift fiir physiologische Chemie.



Determination of the Composition of Carbon Compounds

Determination of the Molecular Formula .

The Chemical Constitution of the Carbon Compounds

The Nomenclature of the Carbon Compounds .

Physical Properties of the Carbon Compounds . .

Heat of Combustion of Carbon Compounds

Action of Heat, Light, and Electricity upon Carbon Compounds

The Direct Combination of Carbon with other Elements

Classification of the Carbon Compounds . . .




18 42

43 60 61






A. Saturated or Limit Hydrocarbons, Paraffins, Alkanes, Marsh Gas or Methane

Hydrocarbons ........... 69

B. Unsaturated Hydrocarbons. I. Olefines or Alkylenes, 79 ; 2. Acetylenes or

Alkines, 85 ; 3. Diolefines, 90; 4. Olefine Acetylenes, 91 ; 5. Diacetylenes,

91 ; 6. Triolefines . . . . . . . . . .91






Monohydric Alcohols, 100. A. Saturated Alcohols, Paraffin Alcohols . . 109 B. Unsaturated Alcohols, 123. I. Olefine Alcohols, 123 j 2. Acetylene

Alcohols, 125 ; 3. Diolefine Alcohols ...... 125

Alcohol Derivatives. I. Simple and Mixed Ethers, 125 ; 2. Esters of the Mineral Acids, 130; 3. Sulphur Derivatives of the Alcohol

Radicals . 142

4. Selenium and Tellurium Compounds ...... 148

5. Nitrogen Derivatives of the Alcohol Radicals ..... 148

6. Phosphorus Derivatives of the Alcohol Radicals . . . . *73


7. Alkyl Derivatives of Arsenic, 175 ; 8. Antimony, 179 ; 9. of Bismuth 179; 10. of Boron, 180 ; n. of Silicon, 180 ; 12. of Germanium

13. Tin Alkyl Compounds .

14. Metallo-organic Compounds .......

2. Aldehydes, and 3. Ketones

2A. Aldehydes of the Saturated Series

1. Halogen Substitution Products of the Saturated Aldehydes Peroxides of the Aldehydes

2. Ethers and Esters of Methylene and Ethylidene Glycols

3. Sulphur Derivatives of the Saturated Aldehydes

181 182

183 189 191

201 203

2O4 208

4. Nitrogen Derivatives of the Aldehydes . ' . . . .210

2B. Olefine Aldehydes 214

2C. Acetylene Aldehydes . . . . . . . . .215

3 A. Ketones of the Saturated Series 216

1. Halogen Substitution Products of the Ketones .... 224

2. Alkyl Ethers of the Ortho-ketones 225

3. Ketone Halides 225

4. Ketone Bisulphites and Sulphoxylates . . . . .225 .5. Sulphur Derivatives of the Saturated Ketones .... 225

6. Nitrogen Derivatives of the Ketones ..... 226

36. Olefine and Diolefine Ketones ....... 228

3C. Acetylene Ketones 232

Monobasic Carboxylic Acids ......... 232

A. Monobasic Saturated Acids . . . . . ..... 235

Derivatives of the Fatty Adds 265

1. Esters of the Fatty Acids 265

2. Acid Halides of the Fatty Acids 269

3. Acid Anhydrides . . . . . . . .271

4. Acid Peroxides ......... 273

5. Thio-Acids . . . . 273

6. Acid Amides ......... 274

7. Acid Hydrazides 278

8. Acid Andes 278

9. Fatty Acid Nitriles 278

10. Amide Chlorides 281

11. Imide Chlorides ......... 281

12. Imido-Ethers 281

13. Thiamides 281

14. '1 hio-imido-Ethers . . . . . . . . 282

15. Amidines . . . . . . ' . . . 282

16. Hydroxamic Acids ........ 282

17. Hydroximic Acid Chlorides ...... 283

18. Nitrolic Acids 283

19. Amidoximes or Oxamidines ....... 283

20,21. Hydroxamic Oxime ; Nitrosoximes ..... 284

22, 23. Hydrazidine and Hydrazo-oxime ..... 284

24. Ortho-fatty Acid Derivatives ...... 284

Halogen Substitution Products of the Fatty Acids . . . 284

B. Oleic Acids, Olefine Monocarboxylic Acids ..... 290

C. Acetylene Carboxylic Acids ........ 302

D. Diolefine Carboxylic Acids 305



I. Dihydric Alcohols or Glycols 307

Glycol Derivatives . . . . . . . . . .316

1. Alcohol Ethers of the Glycols ...... 316

2. Esters of the Dihydric Alcohols ...... 319

3. 1 hio-Compounds of Ethylene Glycols 324

4. Nitrogen Derivatives of the Glycols ...... 327



2. Aldehyde-Alcohols, 337 ; Nitrogen-containing Derivatives of the Aldehyde-

Alcohols ............ 339

3. Ketone- Alcohols or Ketols, 340 ; Nitrogen-containing Derivatives of the

Ketone-Alcohols ........... 344

4. Dialdehydes ............ 346

5. Ketone-Aldehydes, or Aldehyde-Ketones . . . . . . . 348

6. Diketones, 348 ; Nitrogen-containing Derivatives of the Dialdehydes, Alde-

hyde-Ketones and Diketones ........ 353

7. Alcohol- or Hydroxy-acids ......... 356

A. Saturated Hydroxymonocarboxylic Acids, 362 ; o-Hydroxy-acids, 362 ;

/8-Hydroxycarboxylic Acids, 369; 7- and 0-Hydroxy-acids, 371; Sulphur Derivatives of the Hydroxy-acids, 376 j Nitrogen Derivatives of the Hydroxy-acids, 378 ; Amino-Fatty Acids, 385 ; Dipeptides and Polypeptides ......... 390

B. Unsaturated Hydroxy-acids, Hydroxy-olefine Carboxylic Acids . . 397

8. Aldehyde-acids, 400 ; Nitrogen Derivatives of the Aldehyde-acids . . . 402

9. Ketonic Carboxylic Acids .......... 406

A, Saturated Ketone Carboxylic Acids. I. o-Ketonic Acids, 407 ; Nitrogen

Derivatives of the o-Ketonic Acids, 409. II. ^-Ketonic Acids, 410 ; Acetoacetic Acid, 410 ; Nitrogen Derivatives of j8-Ketonic Acid, 419 ; Halogen Substitution Products of the £-Ketonic Esters, 420. III. 7-Ketonic Acids, 421 ; Nitrogen Derivatives of the 7-Ketonic Acids, 423. IV. 5-Ketonic Acids 424

B. Unsaturated Ketonic Acids ; Olefine Ketonic Acids .... 425


Chlorides of Carbonic Acid, 430 ; Sulphur Derivatives of Ordinary Carbonic Acid . 431

Amide Derivatives of Carbonic Acid, 435 ; Carbamide Urea, 4^8 ; Ureides, 441 ; Hydrazine-, Azine-, and Azido-Derivatives of Carbonic Acid, 446 ; Sulphur-containing Derivatives of Carbamic Acid and of Urea . . . 448

Guanidine and its Derivatives ......... 454

Nitriles and Imides of Carbonic and Thiocarbonic Acids, 459 ; Oxygen Deriva- tives of Cyanogen, their Isomerides and Polymerides, 460 ; Halogen Com- pounds of Cyanogen and its Polymers, 465 ; Sulphur Compounds of Cyanogen, their Isomers and Polymers, 466 j Cyanamide and the Amides of Cyanuric Acid, 471 ; Ketenes ........ 474

10. Dibasic Acid, Dicarboxylic Acids ........ 476

A. Paraffin Dicarboxylic Acids, 476 ; Oxalic Acid and its Derivatives, 480 ;

Nitriles of Oxalic Acid, 484 ; the Malonic Acid Group, 487 ; Carbon Suboxide, 488 ; Ethyl ene Succinic Acid Group, 491 ; Nitrogen- containing Derivatives of the Ethylene Succinic Acid Group, 496 ; Halogen Substitution Products of the Succinic Acid Group, 499 ; Glutaric Acid Group, 501 ; Group of Adipic Acid and Higher Normal Paraffin Dicarboxylic Acids ...... 504

B. Olefine Dicarboxylic Acids, 507 ; Fumaric Acid, 509 ; Maleic Acid,

510; The Isomerism of Fumaric and Maleic Acids, 512; Itaconic Acid, 515 ; Citraconic Acid, 516; Mesaconic Acid . . . 516



1. Trihydric Alcohols, 524. A. Glycerol Esters of Inorganic Acids, 529. B.

Glycerol Fatty Acid Esters, Glycerides, 530 ; Glycerol Ethers, 531 ;

Nitrogen Derivatives of the Glycerols ... ... 533

2. Dihydroxy- Aldehydes 533

3. Dihydroxy-Ketones (Oxetones) 534

4. Hydroxy-Dialdehydes 535

5. Hydroxy- Aldehyde Ketones S36



6. Hydroxy-Ketones ....... 8 ... 536

7. Dialdrhyde K clones .......... 537

8. Aldehyde Diketones .......... 537

9. Triketones ............ 537

10. Dihydroxy-monocarboxylic Acids, 538 ; Monoamino-hydroxy-carboxylic Acids,

540; Monoamino-thio-carboxylic Acids, 541; Diamino-monocarboxylic Acids, 542 ; Dihydroxy-olefine Monocarboxylic Acids .... 543

11, 12. Aldo-hydroxy-carboxylic Acids, and Hydroxy-keto-carboxylic Acids . 543

13. Aldehydo-ketone Carboxylic Acids ...... . 545

14. Diketo-carboxylic Acids 546

15. Monohydroxy-dicarboxylic Acids.

A. Monohydroxy- Paraffin D carboxylic Acids 548 Hydroxymalonic Acid Group ........ 549

Hydroxysuccinic Acid Group . . . . . . . . 551

Aminosuccinic Acids . . . . . . . . -553

Hydroxyglutaric Acid Group ........ 558

B. and C. Hydroxy-olefine Carboxylic Acids and Hydroxy-olefine Dicar-

boxylic Acids .......... 560

16. Aldodicarboxylic Acids. A. j8-Aldodicarboxylic Acids, 561. B. 7-Aldodi-

carboxylic Acids . . . . . . . . . . .561

17. Ketone-dicarboxylic Acids, 562 ; Ketomalonic Acid Group, 562 ; Nitrogen

Derivatives of Mesoxalic Acid, 563 ; Ketosuccinic Acid Group, 564 ; Nitrogen Derivatives of Oxalacetic Acid, 567 ; Ketoglutaric Acid Group, 568 ; Olefine- and Di-olefine-Ketone Dicarboxylic Acids . . . -571 Uric Acid Group: Urei'des or Carbamides of Aldehyd- and Keto-Mono- carboxylic Acids, 572 ; Urei'des or Carbamides of Dicarboxylic Acids, 575 ; Diureides, 580 ; Oxidation of Uric Acid, 584 ; Synthesis of Uric Acid, 585 ; Conversion of Uric Acid into Xan thine, Guanine, Hypoxan thine and Adenine, 587 ; Synthesis of Heteroxanthine, Theobromine, and Paraxan- thine 590

18. Tricarboxylic Acids : A. Saturated Tricarboxylic Acids, 592 ; B. Olefine

Tricarboxylic Acids 594



1 Tetrahydric Alcohols 596

2 Trihydroxyaldehydes ; 3. Trihydroxyketones . ... . . 597

4 Hydroxytriketones ........... 597

Tetraketones ............ 597

Trihydroxy-monocarboxylic Acids . . . . . . . . 598

Dihydroxyketo-monocarboxylic Acids 598

Hvdroxydiketo-carboxylic Acids 598

9. Triketo-monocarboxylic Acids 598

10. Dihydroxy-dicarboxylic Acids : A. Malonic Acid Derivatives, 599 ; B.

Succinic Acid Derivatives, 599 ; Synthesis of Racemic Acid, 601 ; C.

Glutaric Acid Derivatives, 605 ; D. Adipic Acid Derivatives and Higher v

Homologues ........... 606

11. Hydro xy-keto-dicarboxylic Acids 607

12. Diketone Dicarboxylic Acids 607

13. Hydroxytricarboxylic Acids ......... 610

14. Ketone Tricarboxylic Acids 612

15. Tetracarboxylic Acids: A. Paraffin Tetracarboxylic Acids, 613; B. Olefine

Tctracarboxylic Acids 615



1. Pentahydric Alcohols, Pentitols .

2. Tetrahydroxyaldehydes, Aldopentoses

3. Tetrahydroxymonocarboxylic Acids

4. Trihydroxydicarboxylic Acids .

5. Dihydroxy-ketone Dicarboxylic Acids

6. Triketone Dicarboxylic Acids

7. Dihydroxytricarboxylic Acids .

8. Pentacarboxylic Acids

615 616 619 621 621 621 621 622



I A. Hexhydric Alcohols, Hexahydroxyparaffins, Hexitols - ,. . . . 622

I B. Heptahydric Alcohols .......... 624

i C. Octahydric Alcohols . *',*.. 625

1 D. Nonohydric Alcohols 625

2, 3. Penta-, Hexa-, Hepta-, and Octo-Hydroxyaldehydes and Ketones . . 625

2 A. Pentahydroxyaldehydes, and 3 A. Pentahydroxyketones, Hexoses, Dextroses

(Glucoses), Monoses . . . . . . . . 626

2 A. Aldohexoses . . . v . . . , . ./. . . . 631

3 A. Ketohexoses 635

2 B. Aldoheptoses j 2 C. Aldo-octoses ; 2 D. Aldononoses .... 637

The synthesis of Grape-sugar or d-Dextrose, and of Fruit-sugar or d-Fructose. 637

A. The Space-Isomerism of the Pentitols and Pentoses, the Hexitols and

Hexoses ........... 639

B. The Space-Isomerism of the Simplest Hexitols and the Sugar-Acids, the

Aldohexoses and the Gluconic Acids . . . . . .641

Derivation of the Space-formula for d-Dextrose or Grape-sugar . . 643

Derivation of the Configuration of d-Tartaric Acid . . . . 646

4. Hexaketones ............ 647

5. PolyhydroxymoRocarboxylic Acids . . . . . . . 647

A. Pentahydroxycarboxylic Acids 647

B. Hexose Carboxylic Acids, Hexahydroxymonocarboxylic Acids . . 651

C. Aldoheptose Carboxylic Acids, Heptahydroxycarboxylic Acids . .651

D. Aldo-octose Carboxylic Acids, Octohydroxycarboxylic Acids . . 652

6. Tetrahydroxy- and Pentahydroxy-Aldehyde Acids « 652

7. Monoketotetrahydroxycarboxylic Acids . . . . . . . 652

8. Pol> hydro xydi Carboxylic Acids: A. Tetrahydroxydicarboxylic Acids, 652 ;

B. Pentahydroxydicarboxylic Acids . ... 655

9. Tetraketodicarboxylic Acids . . ' ;' ' . . . 655

10. Triketo-tricarboxylic Acids ... . . 655

11. Hydroxyketotetracarboxylic Acids

12. Diketotetracarboxylic Acids . ^ „_

Appendix : Higher Polycarboxylic Ethyl Esters . . - » - * . . 656



A. Disaccharides ; Saccharobioses .......•• 657

B. Trisaccharides j Saccharotrioses 66l

C. Polysaccharides, 66 1 ; Nitrocelluloses ....... 664



Proteins, Albumins, 666 ; a Monamino-monocarboxylic Acids, 666 ; b Mon- amino-dicarboxylic Acids, 666 ; c Hydroxamino-, Thioamino, Diamiuo-,

Imino- Acids . . . . . . .-.*..'. . . ' . 667

A. Glucoproteins ............. 071

B. Phosphoprote'ins ... . 672

C. Gelatin (Derivatives of Intercellular Materials) ••;"•• . . . 673

D. Haemoglobins, 674 ; Chlorophyll . ' . . . . . . . 675

E. Biliary Substances . . . .- . . . . . . 676

F. Unorganized Ferments or Enzymes ........ 677

INDEX «... . ' '. . . 679





WHILST inorganic chemistry was developed primarily through the investigation of minerals, and was in consequence termed mineral chemistry, it may be said that the development of organic chemistry was due to the study of products resulting from the alteration of plant and animal substances. About the close of the eighteenth century Lavoisier demonstrated that, when the organic substances present in vegetable and animal organisms were burned, carbon dioxide and water were always formed. It was this chemist also who showed that the component elements of these bodies, so different in properties, were generally carbon, hydrogen, oxygen, and, especially in animal substances, nitrogen. Lavoisier further gave utterance to the opinion that peculiarly constituted atomic groups, or radicals, were to be accepted as present in organic substances ; whilst the mineral sub- stances were regarded by him as the direct combinations of single elements.

As it seemed impossible, for a long time, to prepare organic bodies synthetically from the elements, the opinion prevailed that there existed an essential difference between organic and inorganic sub- stances, which led to the use of the names Organic Chemistry and Inorganic Chemistry. The prevalent opinion was, that the chemical elements in the living bodies were subject to other laws than those in the so-called inanimate nature, and that the organic substances were formed in the organism only by the intervention of a peculiar vital force, and that they could not possibly be prepared in an artificial way.

One fact sufficed to prove these rather restricted views to be un- founded. The first organic substance artificially prepared was urea (Wohler, 1828). By this synthesis chiefly, to which others were soon added, the idea of a peculiar force necessary to the formation of organic compounds was contradicted. All further attempts to separate organic substances from the inorganic (the chemistry of the simple and the chemistry of the compound radicals, p. 18) were futile. At present we know that these do not differ essentially from each other ;



that the peculiarities of organic compounds are dependent solely on the nature of their essential constituent, Carbon ; and that many sub- stances belonging to plants and animals can be prepared artificially from the elements. Organic Chemistry is, therefore, the chemistry oj the carbon compounds. Its separation from the chemistry of the other elements is necessitated only by practical considerations, on account of the very great number of carbon compounds (about 120,000 : see M. M. Richter's Lexikon der Kohlenstoffverbindungen), which far exceeds those of all other elements put together. No other possesses in the same degree the ability of the carbon atoms to unite with one another to form open and closed rings or chains. The numerous existing carbon nuclei in which atoms or atomic groups of other elements have entered in the formation of organic derivatives have arisen in this manner.

The impetus given to the study of the compounds of carbon has not only brought new industries into existence, but it has caused the rapid development of others of like importance to the growth and welfare of the nation.*

The advances of organic chemistry are equally important to the investigation of the chemical processes in vegetable and animal organisms, a section of the subject known as Physiological Chemistry.



Most carbon compounds occurring in the animal and vegetable kingdoms consist of carbon, hydrogen, and oxygen, as was demonstrated by Lavoisier, the founder of organic elementary analysis. Many, also, contain nitrogen, and on this account these elements are termed OrganogensJ whilst sulphur and phosphorus are often present. Almost all the elements, non-metals and metals, may be artificially introduced as constituents of carbon compounds in direct union with carbon. The number of known carbon compounds is exceedingly great (see above). The general procedure, therefore, of isolating the several compounds of a mixture, as is done in inorganic chemistry in the separation of bases from acids, is impracticable, and special methods have to be devised. The task of elementary organic analysis is to determine, qualitatively and quantitatively, the elements of a carbon compound after it has been obtained in a pure state and characterized by definite physical properties, such as crystalline form, specific gravity, melting point, and boiling point. Simple practical methods for the direct determination of oxygen do not exist ; its quantity is usually calculated by difference, after the other constituents have been found.

* Wirthschaftliche Bedeutung chemischer Arbeit, von H. Wichelhaus, 1893. f This word is retained here from the German, but is not in general use in Euj lish chemical language. (Translator's note.)



The presence of carbon in a substance is shown by its charring when ignited out of contact with air. In general its quantity, as also that of the hydrogen, is ascertained by combustion. The substance is mixed in a glass tube with copper oxide and heated, or the vapour of the substance is passed over red-hot copper oxide. The cupric oxide gives up its oxygen and is reduced to metallic copper, whilst the carbon burns to carbon dioxide, and the hydrogen to water. In quantitative analysis, these products are collected separately in special apparatus, and the increase in the weight of the latter determined. Carbon and hydrogen are always simultaneously determined in one operation. The details of the quantitative analysis are fully described in the text- books of analytical chemistry.* It is only necessary here, therefore, to outline the methods employed. Liebig's name is especially associ- ated with the elaboration of these methods (Pogg. A. 1831, 21, i).

Usually the combustion is effected by the aid of copper oxide or fused and granulated lead chromate in a tube of hard glass, fifty to seventy centimetres long (depending upon the greater or less volatility of the organic body). Substances which burn with difficulty should be mixed with finely divided cupric oxide, finely divided lead chromate, or with cupric oxide to which potassium bichromate has been added.

The combustion tube is drawn into a point, and the contracted end given a bayonet-shape (Liebig), or it is open at both ends (Glaser, A. Suppl. 7, 213). Chez has also suggested the use of an iron tube (Z. anal. Ch. 2, 413).

The tube is placed in a suitable furnace, which formerly was heated by a char- coal fire, but at present gas is usually employed (A. W. Hofmann, A. 90, 235 ; 107, 37 ; Erlenmeyer, ST., A. 139, 70 ; Glaser, I.e. ; Anschiitz and Kekule, A. 228, 301 ; Fuchs, B. 25, 2723). Recently electric heating has been adopted with success (comp. B. 39, 2263).

When the tube has been charged, the open end is attached to an apparatus designed to collect the water produced in the combustion. The substances used to retain the moisture are :

1. A U-tube filled with carefully purified calcium chloride, which has been dried at 180° C.

2. Pure, concentrated sulphuric acid contained in a specially designed tube, or pumice fragments, dipped in the acid, and placed in a U-tube (Mathesius, Z. anal. Ch. 23, 345).

3. Pellets of glacial phosphoric acid, contained in a U-tube. The vessel intended to receive the water is in air-tight connection with the apparatus designed to absorb the carbon dioxide. For the latter purpose a Liebig potash bulb was formerly employed, but later that of Geissler came into use ; and very many other forms have been recommended (B. 24, 271 ; C. 1900," 1, 1240). U -tubes, filled with granulated soda-lime, are substituted for the customary bulbs (Mulder, Z. anal. Ch. 1, 2).

When the combustion is finished, oxygen free from carbon dioxide is forced into or drawn through the combustion-tube, air being substituted for it later, with the precaution that the pieces of apparatus serving to dry the oxygen and air are filled with the same material which was used for absorbing the water produced by the combustion. As soon as the entire system is filled with air, the pieces of apparatus employed for absorbing the water and carbon dioxide are disconnected and weighed separately. The increase in weight of the apparatus in which the water is collected represents the water resulting from the combustion of the

* Anleitung zur Analyse organischer Korjjpr, J. Liebig. 2. Aufl. 1853. Quantitative chemische Analyse, R. Fresenius. 6. Aufl., Bd. 2. Chemische Analyse organischer Stoffe, von Vortmann. Die Entwicklung der organischen Elementaranalyse, M. Dennstedt, 1899.


weighed substance, and the increase in the other the quantity of carbon dioxide. Knowing the composition of water and carbon dioxide the quantity of carbon and hydrogen contained in the burnt substance can readily be calculated in percentage.

Fig. i represents one end of a combustion furnace of the type devised by Kekult and Anschfitz (A. 228, 301). In it lies the combustion tube V. This is connected with a Klinger calcium chloride tube, A ; B is a Geissler potash-bulb, joined to a U-tube, C, one limb of which is filled with pieces of stick potash, and the other with calcium chloride. G represents mica plates, which permit of a careful observation of the flame. £ is a section of the iron tube (Modification, C. 1903, 1, 609) in which the combustion tube V rests; T a side clay cover placed over the mica strips ; D a clay cover for the top. R is the gutter into which the gas-pipe, bearing the burners, is placed, and from which it can be removed for repair, etc.

FIG. i.

Fig. l also shows, above the combustion tube, the anterior portion of a similar tube V1. provided with a Bredt and Posth (A. 285, 385) calcium chloride tube A1, in which the movement of a drop of water enables the analyst to determine the rapidity of the combustion. B1 is a U-tube filled with soda-lime and provided with ground-glass stoppers. C1 is a similar tube, filled one-half with soda-lime and one-half with calcium chloride.

Instead of oxidizing the organic substance with the combined oxygen of cupric oxide or lead chromate, the method of Kopfer may be employed, in which platinum black is made to carry free oxygen to the vapours of the substance. A simpler combustion furnace may then be employed.

This method has been perfected by Dennstedt * and his co-workers. In his " rapid combustion method " the substance is introduced into a small tube and vapourized therefrom into a slow stream of oxygen. At the same time a more rapid current of the gas is sent round the small containing tube and over the heated contact substance (thin strips of platinum foil), so that the vapour of the compound to be combusted is always in the presence of a large excess of oxygen. The accompanying illustration (Fig. 2) indicates clearly the arrangement (B. 38, 3729; 39, 1623). p^

* Dennstedt, Anleitung zur vereinfachten Elementar-analyse, 2. Aufl. Hamburg, 1906.


Dudley recommends that the substance be placed in a boat and burned in a platinum tube containing granular manganese dioxide in the anterior part (B. 21, ^172). Or the substance may be combusted in a drawn-out copper tube (C. 1898, 2,305).

Methods for the complete combustion of solid carbon compounds have been worked out by W. Hempel, Krockey, as well as by Zuntz and Frentzel (B. 30, 202, 380, 605), by which the substance is completely burned in oxygen under pressure in an autoclave.

Gaseous bodies can be analysed according to the usual gas analysis methods, either with Bunsen's * apparatus, or with Hempel' s,f when great accuracy is not required. The volume of the gas or mixture of gases is measured after each successive reaction with potassium hydroxide solution, fuming sulphuric acid, alkaline pyrogallic acid and ammoniacal cuprous chloride. These reagents absorb respectively carbon dioxide, the so-called heavy hydrocarbons (defines, acetylene, aromatic hydrocarbons of the CnH2;l_6 series), oxygen and carbon monoxide. The gaseous residue, which may consist of nitrogen, hydrogen and methane, is either exploded with oxygen and the contraction in volume measured both before and after absorption of the carbon dioxide formed ; or else the two combustible gases may be separately dealt with, the hydrogen being absorbed by paladium

FIG. 2.

black and the methane being led over incandescent platinum. A complete separation of the ethylene hydrocarbons from those of the benzene series has often been attempted, but the results have not been satisfactory.

When nitrogen is present in the substances burned, its oxides are sometimes produced, which have to be reduced to nitrogen. This may be effected by con- ducting the gases of the combustion over a layer of metallic copper filings, or a roll of copper gauze placed in the front portion of the combustion tube. The latter, in such cases, should be a little longer than usual. The copper, which has been previously reduced in a current of hydrogen, often includes some of the gas which, on subsequent combustion, would yield water. To remedy this, the copper after reduction is heated in an air-bath or, better, in a current of carbon dioxide or to 200° in a vacuum. Its reduction by the vapours of formic acid or methyl alcohol is more advantageous ; this may be done by pouring a small quantity of these liquids into a dry test tube and then suspending in them the roll of copper heated to redness ; copper thus reduced is perfectly free from hydrogen.

It is generally unnecessary to use a copper spiral when the combustions are carried out in open tubes.

If the substance contains chlorine, bromine or iodine, copper halides are formed, which, being volatile, would pass into the calcium chloride tube. In order to avoid this a spiral of thin copper, or better, silver foil is introduced into the front

* Bunsen, Gasometrische Methoden, 2. Aufl, Braunschweig, 1877. t Hempel, Gasometrische Methoden, Braunschweig, 1900. Winkler, Gas- analyze, Freiberg, 1901.


part of the tube. When the organic compound contains sulphur a portion of the latter will be converted into sulphur dioxide (during the combustion with cupric oxide), which may be prevented from escaping by introducing a layer of lead peroxide (Z. anal. Ch. 17, i). Or lead chromate may be substituted for the cupric 'oxide, which would convert the sulphur into non-volatile lead sulphate. In the combustion of organic salts of the alkalies or alkaline earths, a portion of the carbon dioxide is retained by the base. To prevent this and to expel the CO2, the substance in the boat is mixed with potassium bichromate or chromic oxide (B. 13, 1641).

An organic substance, containing nitrogen, sulphur, chlorine or bromine, can be analysed by Dennstedt's method (see above, Fig. i). It is mixed with pure lead peroxide and placed in a boat of special shape in the front part of the tube. The temperature is then raised to about 320°. The nitrogen, sulphur, and halogens are held back in the form of lead compounds, whilst the carbon and hydrogen pass away as carbon dioxide and water, and are estimated in the usual way.

When carbon alone is to be determined this can be effected, in many instances, in the wet way, by oxidation with chromic acid and sulphuric acid (Messinger, B. 21, 2910 ; compare A. 273, 151).


In many instances, the presence of nitrogen is disclosed by the odour of burnt feathers when the compounds under examination are heated. Many nitrogenous substances yield ammonia when heated with alkalies (or, better still, with soda-lime) . A simple and very delicate test for the detection of nitrogen is the following : the substance is heated in a test tube with a small piece of sodium or potassium, or, when the substance is explosive, with the addition of dry soda. Potassium cyanide is produced, accompanied perhaps by a slight detonation. The residue is treated with water ; to the nitrate, ferrous sulphate containing a ferric salt is added, and then a few drops of potassium hydroxide ; the mixture is then heated, and finally an excess of hydro- chloric acid is added. An undissolved, blue-coloured precipitate (Prussian blue), or a bluish-green coloration, indicates the presence of nitrogen in the substance examined.

Nitrogen is determined quantitatively : (i) as nitrogen, by the method of Dumas ; (20) as ammonia, by the ignition of the material with soda-lime (method of Will and Varr entrap) ; (26) as ammonia, by heating the substance with sulphuric acid according to the direc- tions of Kjeldahl.

i. Dumas' Method. The substance, mixed with cupric oxide, is burned in a tube of hard glass in the anterior end of which is a layer of metallic copper which serves for the reduction of the oxides of nitrogen. The tube is filled with carbon dioxide, obtained by heating either dry, primary sodium carbonate or magnesite, contained in the posterior and closed end of the tube. It can also be filled from a carbon dioxide apparatus of the type recommended by Kreusler (Z. anal. Ch, 24, 440), in which case an open tube is used. A more practicable method of procedure consists in evacuating the tube, previous to the combustion, by means of an air-pump, and filling each time with carbon dioxide (A. 233, 330, note) ; or the air may be removed by means of a mercury pump (Z. anal. Ch. 17, 409).

When the combustion is ended, excess of carbon dioxide is employed to sweep all the nitrogen from the combustion tube into the graduated tube or azotomeier, which may have one of a variety of forms (Zulkowsky, A. 182, 296 ; B. 13, 1099 ; Schwarz, B. 13, 771 ; Ludwig, B. 13, 883 ; H. Schiff, B. 13, 885 ; Staedel, B. 13, 2243 ; Groves, B. 13, 1341 ; Ilinski, B. 17, 1348). The potassium hydroxide in the graduated vessel absorbs all the disengaged carbon dioxide, and only pure nitrogen remains.


Given the volume V^ of the gas, the barometric pressure p and the vapour- pressure s of the potassium hydroxide (Wullm-r, Pogg. A. 103, 529; 110, 564) at the temperature t of the surrounding air, the volume V0 at and 760 mm. may be easily deduced :


760 (1+0-0036650

Multiply V0 by 0-0012507, the weight of i c.c. of nitrogen at and 760 mm., and the product will represent the weight in grams of the observed volume of nitrogen :

760 (

from which the percentage of nitrogen in the substance analysed can easily be calculated.

Instead of reducing the observed gas volume V, from the observed barometric pressure and the temperature at the time of the experiment, to the normal pressure of 760 mm. and the temperature of (" N.T.P."), the reduction may be more readily effected by comparing the observed volume of gas or vapour with the expansion of a normal gas- volume (100) measured at 760 mm. and o°. For this

purpose the equation V0=V.-^ is employed, in which v represents the changed

normal volume (100). The gas-volumometer recommended by Kreusler (B. 17, 30) and Winkler (B. 18, 2534), or the Lunge nitrometer (B. 18, 2030 ; 23, 440 ; 24, 1656, 3491 l J.A. Muller, B. 26, R. 388) will answer very well for this purpose. Or the nitrogen may be collected in a gas-baroscope, and its weight calculated from the pressure of a