IC-NRLF 
 
 SB E77 77E 
 
 'e* ., ' 
 
LIBRARY 
 
 OF THE 
 
 UNIVERSITY OF CALIFORNIA. 
 
 OF* 
 
 Ctes 
 
SOME 
 
 REACTIONS OF ACETYLENE 
 
 DISSERTATION 
 
 SUBMITTED TO THE FACULTY OF PHILOSOPHY OF THE CATHOLIC 
 
 UNIVERSITY OF AMERICA FOR THE DEGREE OF 
 
 DOCTOR OF PHILOSOPHY 
 
 BY 
 
 JULIUS A. NIEUWLAND, C. S. C. 
 
 NOTRE DAME UNIVERSITY PRESS 
 
 NOTRE DAME, INDIANA 
 IQ04 
 
ACKNOWLEDGMENT. 
 
 The work about to be described was suggested by 
 Prof. John J. Griffin and carried on under his guid- 
 ance. I express to him ray sincere thanks for the 
 kind counsel and instruction received during my 
 course of chemistry at the Catholic University. I 
 gratefully acknowledge my obligations also to Prof. 
 E. Greene, Prof. E. Pace, and Dr. T. Shields, under 
 whom I pursued my studies in botany, experimental 
 psychology, and biology respectively. 
 
THE HYDROGENATION OF ACETYLENE. 
 
 THE HISTORY OF THE SYNTHESIS OF ETHYI.ENE. 
 
 Numerous attempts have been made to unite acet- 
 ylene with hydrogen to form ethylene or ethane. 
 The first combination of acetylene with hydrogen 
 was effected by Wilde, 1 who united them by pass- 
 ing the gases over platinum black, ethylene being 
 formed. The residual gas did not give the acetylene 
 reaction with ammoniacal cuprous chloride, and was 
 absorbed by fuming sulphuric acid. 
 
 Berthelot 2 succeeded in obtaining ethylene from 
 acetylene given off from copper acetylide in the pres- 
 ence of nascent hydrogen. The gases were obtained 
 from zinc and from copper acetylide in ammonia 
 water. Hydrogen from an acid solution did not give 
 a good yield of ethylene. The ethylene was separ- 
 ated from the acetylene with difficulty, as the two 
 hydrocarbons dissolved in the ammoniacal cuprous 
 chloride. The latter gas, however, formed a precipi- 
 tate of copper carbide, from which the acetylene 
 could be determined gravimetrically, and the ethylene 
 could be calculated volumetrically by boiling the solu- 
 tion of the cuprous chloride, when the gas was 
 evolved from the solution, and measured after wash- 
 ing free from ammonia. 
 
 1 Ber. 7. 353. (Bull, d' Acad. Royal de Belg. 2, XXI., 
 No. i. (1864). 
 
 2 Ann. Chim. Phys. 3, LXVIL, 51, (1863.) 
 
 3 
 
 1 57' 
 
- 4 - 
 
 Berthelot 1 likewise showed that when a mixture of 
 hydrogen and acetylene was heated, ethylene was one of 
 the products. He accounted for the formation of the 
 ethylene in two ways, first by direct addition, when 
 the action represented by the equation, C 2 H 2 H-H 2 = 
 C 2 H 4 , took place. As, however, the yield of the 
 ethyleue was too small to correspond to this reaction, 
 another mode of formation was suggested, namely : 
 2C 2 H 2 = C 2 H 4 -f-2C. Ethylene likewise underwent 
 decomposition into acetylene and ethane : 2C 2 H 4 = 
 C 2 H 2 +C 2 H 6 . If hydrogen were present it united 
 with the ethylene to form ethane. 
 
 In 1895, N. Caro 2 claimed that he had obtained 
 alcohol from acetylene. This gas and hydriodic acid 
 gave ethylene di-iodide, or ethylidene di-iodide, and 
 this product being boiled with a concentrated solution 
 of caustic potash gave potassium acetate, acetylene 
 and alcohol. Seventy grams of alcohol were said to 
 have been obtained in one operation. When the 
 di-iodide was decomposed with silver hydroxide, only 
 small quantities of acetylene were obtained, together 
 with 90 percent, potassium acetate and alcohol. (!) 
 The di-iodide of ethylene heated in closed tubes with 
 water gave a yield of alcohol that amounted to 40 
 per cent, of the theoretical. 
 
 Kru'ger and Pueckert 3 repeated Caro's work, and 
 found that they could make 50 grams of di-iodide 
 in three months and from this no alcohol could be 
 obtained, though aldehyde was shown to be present. 
 
 1 Ann. Chim. Phys. 4, IX., 431. 
 
 2 Cent. (1895) 2, 437. Chem. Ind. 18, 226. 
 
 3 Chem. Ind. 18, 454. 
 
5 
 
 Caro repeated his work, but could not obtain his 
 previously published results and acknowledged his 
 mistake. 
 
 Kru'ger 1 could not, moreover, succeed in uniting 
 acetylene with nascent hydrogen, as Berthelot 2 had 
 claimed. In 1894, an article was published by 
 Frank 3 advocating the commercial manufacture of 
 alcohol thus prepared by the action of acetylene on 
 nascent hydrogen. The ethylene formed was to be 
 led into ordinary strong sulphuric acid. This, 
 diluted and boiled with water, would give alcohol. 
 The acid would be again concentrated and used. 
 This process was represented by the following reac- 
 tions : 
 
 C 2 H 2 -{- H 2 = C 2 H 4 , 
 
 HO C 2 H 5 O 
 
 C 2 H 4 + >SO 2 = >SO 2 , 
 
 HO HO 
 
 C 3 H 5 O HO 
 
 > SO 2 + HOH = > S0 2 + C 2 H 5 OH . 
 HO HO 
 
 In 1899 and 1900, Sabatier and Senderens* studied 
 the action of finely divided metals such as nickel, 
 cobalt, copper, and iron on a mixture of hydrogen 
 and acetylene, and found that under certain condi- 
 tions of temperature and time, ethylene, ethane and 
 
 1 Chem. Ind. 18, 459. 
 
 2 Compt. Rend. 54, 515. 
 
 3 Chem. Ind. 18, 74. (1894). 
 
 4 Compt. Rend. 128, 173, and 130, 1559, 1628, 1762. 
 
6 
 
 other hydrocarbons of the aliphatic and aromatic 
 series were obtained. 
 
 In 1902, the addition of hydrogen to acetylene was 
 effected electrolytically by Bilitzer. 1 He electro- 
 lyzed acetylene gas dissolved in a solution of sodium 
 potassium and ammonium hydrates, and in sulphuric 
 acid. In the alkaline electrolytes depolarization with 
 the union of acetylene and the electrolytic hydrogen 
 took place with a platinized platinum cathode, but 
 not with plates of platinum or nickel. In sulphuric 
 acid solutions of acetylene with platinized platinum 
 electrodes the products were ethylene, ethane, and 
 hydrogen, according to the strength of the current 
 used. The hydrogenation of the acetylene was ef- 
 fected only when very weak currents were employed. 
 This seems to show that the action was entirely a 
 mechanical one, for when strong currents were used 
 the platinum electrodes would become coated with 
 gas and prevent the access of the acetylene to the 
 finely divided platinum on the surface of the electrode. 
 The acetylene was absorbed with ammoniacal silver 
 nitrate, the ethylene with fuming sulphuric acid. 
 Hydrogen and ethane were determined by explosion. 
 Bilitzer worked with very small quantities and 
 claimed yields of ethylene and ethane entirely 
 quantitative, measured by the law of electrochemical 
 equivalents. 
 
 In a solution of normal sulphuric acid, alcohol was 
 supposed to be formed at the mercury cathode, pre- 
 sumably due to the reduction of aldehyde formed by 
 
 1 Monats. f. Chem. XX III., 203. 
 
U- 
 
 | UNlVt : 
 XT, 7 
 
 ^*^*5i 
 
 the action of the sulphuric acid on the acetylene. 
 Traces of alcohol were vouched for. The alcohol was 
 indicated by the potassium bichromate and iodoform 
 reactions. The author wished to obviate any mistake 
 and passed acetylene into a portion of the acid with- 
 out using any current. Only the odor of iodoform 
 was noticed. When the current was passed through 
 the solution for the same length of time as in the 
 previous experiment, a fine but perceptible precipitate 
 of iodoform was obtained. Therefore the author con- 
 cluded that in the second instance the precipitate of 
 iodoform was due to the alcohol formed at the 
 cathode. The author did not suppose that acetylene 
 was changed to ethylene in an acid solution, but 
 thought that the aldehyde present, especially at the 
 mercury cathode was reduced to alcohol at that pole. 
 Now this presupposes that the aldehyde was present 
 before the alcohol was formed. Alcohol may have 
 been present, but the iodoform test does not demon- 
 strate its presence when a primary aldehyde is in 
 solution with it. Acetaldehyde will give the iodo- 
 form reaction far more readily than alcohol, 1 and so 
 no reliance can be put in this test. Bilitizer accord- 
 ingly concluded that with platinized platinum elec- 
 trodes depolarization takes place at the cathode, and 
 that the products in an alkaline solution are ethylene, 
 and ethane when low potentials are used. In a sul- 
 phuric acid solution with a cathode of mercury, small 
 quantities of acetylene are changed to traces of 
 alcohol. The improbability of this conclusion will be 
 
 1 Lieben, Ann. Supp. 7,218 and 377. 
 
more evident after considering the results I obtained 
 in the electrolysis of various solvents with electrodes 
 of calcium carbide. 
 
 In the December number of Electrochemical In- 
 dustry of the year 1902, there appeared the review of 
 a patent granted to J. W. Harris, for the manufacture 
 of ether and alcohol, from acetylene by electrolysis. 
 The method, briefly described, is as follows. Acety- 
 lene is introduced into sulphuric acid in a heated 
 vessel, so that the gas passes under a conical cathode 
 of metal. "The acetylene is said to unite with the 
 nascent hydrogen at the cathode to form ethylene. 
 This unites with sulphuric acid to form ethyl sul- 
 phuric acid. The anode is contained in a porous cell 
 to prevent the oxidation of the contents of the cell. 
 When the electrolyte contains over fifty per cent, of 
 water alcohol is formed. As the proportion of the 
 water diminishes the formation of ether begins. 
 Ethane may also be formed but this is to be prevented 
 as much as possible. The formation of the products 
 is thus accounted for : 
 
 C 2 H 2 + H 2 = C 2 H 4 , 
 
 C 2 H 5 
 
 C 2 H 4 -f-H 2 SO 4 = >SO 2 , 
 
 HO 
 
 C 2 H 5 
 
 > SO a + HOH = C 2 H 5 OH+ H 2 SO 4 , 
 HO 
 
 C 2 H 5 
 
 and, 2 >S0 2 +HOH = (C 2 H 5 ) 2 0+2H 2 S0 4 , 
 HO 
 
f\ -.---. 
 
 C 2 H 5 
 
 or, >S0 2 -f-C 2 H 5 OH = H 2 S0 4 +(C 2 H 5 ) 2 O. 
 
 HO 
 
 It was suggested that the union of acetylene with 
 nascent hydrogen might be effected at a cathode of 
 calcium carbide in an electrolyte of appropriate dilu- 
 tion. Before proceeding to this attempt it was deemed 
 necessary to determine the action of sulphuric acid on 
 acetylene and calcium carbide, and whatever simple 
 reactions might take place in such a cell. There is 
 no record of any work done on the action of sulphuric 
 acid on calcium carbide. Whatever work on acety- 
 lene has been done refers to the reaction of the gas 
 itself with sulphuric acid. 
 
 The anode products of the electrolysis were studied 
 by Coehn, 1 in 1901. When a solution of caustic 
 potash was electrolyzed while a stream of acetylene 
 was passed over the anode, formic acid was obtained. 
 Sulphuric acid similarly treated gave acetic acid. 
 
 ACTION OF SULPHURIC ACID ON ACETYLENE. 
 
 That acetylene acted upon sulphuric acid was first 
 perceived by Edmund Davy 2 who discovered the 
 hydrocarbon. He says in the report of his discovery : 
 ' ' The new gas is absorbed to a certain extent by, 
 and blackens sulphuric acid." Berthelot 3 first in- 
 vestigated the products of the reaction of strong sul- 
 phuric acid on acetylene. He obtained an acid, to 
 
 iZeits. f. Elect. 7, 68 1. 
 
 2 Ann. 23, 144. (British Association Reports, 1836, 62.) 
 
 8 Ann. Chim. Phys. (1863), 67, 560. 
 
- 10 
 
 the barium salt of which he assigned the formula, 
 Ba (C 2 H 3 SO 4 ) 2 , and called it barium vinyl sulphate. 
 He claimed that on boiling the acid with water, vinyl 
 alcohol (C 2 H 3 OH) was formed as a decomposition 
 product, in a way analogous to the formation of ethyl 
 alcohol from ethyl sulphuric acid. 
 
 The experiments of Berthelot were repeated by 
 Lagermarck and Eltekow 1 and also by Zeisel. 2 They 
 found that no vinyl alcohol was obtained, but that 
 the product was crotonaldehyde. They ascribed the 
 formation of the crotonaldehyde to the condensation 
 of acetaldehyde with sulphuric acid as Kekule 3 had 
 shown in his attempt to synthesize an aromatic com- 
 pound from acetaldehyde. According to these in- 
 vestigators the mechanism of the transformation of 
 acetaldehyde may be represented by the following 
 reactions : 
 
 CH 3 CH O 
 
 CH H 2 CHO = CH 3 CH:CH CHO+H 2 O. 
 
 Zeisel, however, ascribed the formation of the 
 crotonaldehyde which he found in his repetition of 
 Berthelot 's work to the presence of vinyl haloid im- 
 purities in the acetylene. The gas in all these ex- 
 periments was produced from ethylene bromide, or 
 the copper acetylide, both of which give some vinyl 
 
 1 Ber. 9, 637, and 13, 693. 
 
 2 Ann. 191, 366. 
 
 3 Bull. Soc. Chim. (177), 287, 540. Ber. 3, 604, and Ber. 
 2, 365. 
 
products. Zeisel claimed that in some of his experi- 
 ments he had taken special precautions to eliminate 
 these impurities, and then found that crotonaldehyde 
 was not obtained. When purified acetylene was 
 used, a syrupy sulphonic acid was obtained in small 
 quantity. 
 
 In support of his contentions that vinyl alcohol was 
 obtained from sulphuric acid and acetylene, Berthelot 
 claimed that allylene, a hornologue of acetylene, gave 
 allyl alcohol with sulphuric acid. Schrohe 1 showed 
 that this was ordinary acetone. 
 
 Berthelot 2 next tried the action of acetylene on 
 fuming sulphuric acid, and found that an acetylene 
 sulphonic acid was formed that was not decomposed 
 on boiling in aqueous solution. The salt of this acid 
 gave phenol when fused with caustic potash. Berthe- 
 lot claimed that acetylene was simultaneously poly- 
 merized and oxidized by the caustic alkali. Croton- 
 aldehyde similarly fused yielded no phenol but potas- 
 sium acetate. 
 
 In 1898, Muthman 3 repeated Berthlot's work 
 with fuming sulphuric acid and acetylene. He 
 obtained methionic acid and explained its formation 
 as due to the decomposition of an acid of the sup- 
 
 Ae , 
 po: formula : 
 
 CH(S0 2 OH) 2 
 
 OH _CH(S0 2 OH) 
 
 CH 
 
 1 Inaug. Dissert. Tubingen, 1875. Ber. 8, 367. 
 
 2 Ann. Chim. Phys. 4, XIX., 429, 1870. Ann. 154, 132. 
 
 3 Ber. 31, 1880. 
 
12 
 
 S0 2 + H 2 0. 
 
 The same year Schroeter 1 published the results he 
 obtained in his repetition of Berthelot's work. 
 Schroeter was interested in the claim that Berthelot 
 had succeeded in obtaining phenol from the products 
 of the reaction of acetylene on fuming sulphuric acid, 
 a synthesis quite remarkable from the fact that 
 Kekule had tried to effect the condensation of an 
 aromatic compound from aldehydes without success. 
 None of the products obtained by Schroeter yielded 
 phenol when fused with caustic potash. L,ike Muth- 
 mam he obtained methionic acid. He also obtained 
 the compound from which methionic acid was sup- 
 posed to be a decomposition product, acetaldehyde 
 
 CH(SO a OH) a 
 disulphomc acid, ^^^ 
 
 He obtained among other derivatives its oxime and 
 this fact pointed to the aldehyde formula. There 
 resulted also various sulphates of the above acid with 
 complicated formulas. 
 
 Berthelot repeated his work and came to results 
 that confirmed his first conclusions. He obtained 
 the acetaldehyde disulphonate of potassium as in 
 Schroeter' s experiment. After the separation of this 
 from the solution, other compounds of the formulas, 
 C 2 H 2 (S0 4 KH) 2 , (C 2 H 2 ) 3 (S0 4 KH) 4 , were ob- 
 tained. Examination of these formulas will show 
 that they are of the same empirical composition as 
 
 1 Ber. 31, 2089, an d Ann. 303, 114. 
 
13 
 
 those prepared by Muthman and Schroeter. The 
 compound taken by Schroeter for acetaldehyde disul- 
 phonic acid, or the supposed intermediate product, 
 H 3 C'CH(OSO 2 OH) 2 , is none other than the acid to 
 whose salt Berthelot gave the formula, C 2 H 2 (SO 4 KH) 2 . 
 The other product from which he obtained phenol, 
 namely the compound (C 2 H 2 ) 3 (SO 4 KH) 4 , may cor- 
 respond to a mixture of the sulphates of acetaldehyde 
 disulphonic acid found by Schroeter. 
 
 With dilute sulphuric acid, composed of three vol- 
 umes of strong acid and seven volumes of water, dif- 
 ferent results were obtained by Erdman 1 in 1898. 
 He found that when acetylene was passed into the 
 boiling acid, acetaldehyde was evolved. The forma- 
 tion of the aldehyde was increased in yield by the 
 addition of mercuric oxide, and phosphoric acid gave 
 similar results. 
 
 Much of the work described was repeated in this 
 laboratory with acetylene generated from calcium 
 carbide. This repetition was made necessary in order 
 to understand properly the reactions that are to be 
 expected when sulphuric acid is electrolyzed with 
 calcium carbide electrodes in various strengths of acid. 
 It was also necessary to determine the behaviour of 
 calcium carbide towards sulphuric acid of different 
 strengths. 
 
 ACETYLENE AND STRONG SULPHURIC ACID. 
 
 Acetylene was passed into ordinary strong sul- 
 phuric acid without drying the gas. When the color 
 
 1 Zeits. Anal. Chem. 18, (1898), 55. 
 
- 14- 
 
 of the acid had become very dark the product of the 
 absorption was decomposed with water, and an aqueous 
 solution of crotonaldehyde was obtained. Pure mono- 
 hydrated sulphuric acid also yielded crotonaldehyde. 
 Fuming sulphuric acid, being saturated with acety- 
 lene gave no crotonaldehyde. The principal products 
 were the sulphates of acetaldehyde disulphonic acid 
 referred to by Schroeter. These were obtained as a 
 brown horny mass in the case of the barium salts. 
 
 ACETYLENE AND DILUTE SULPHURIC ACID. 
 
 With sulphuric acid diluted by somewhat more 
 than one half its volume of water, acetaldehyde was 
 obtained when the acid was boiled while acetylene 
 was passed into the flask. The aldehyde was poly- 
 merized by means of a small piece of phosphorus 
 pentachloride placed in a Wolff flask connected with 
 the receiver of the distilling apparatus. 
 
 When hydrogen was passed together with the 
 acetylene into dilute boiling sulphuric acid containing 
 mercuric oxide in suspension , thioaldehyde was most- 
 ly polymerized to trithioaldehyde It possessed the 
 characteristic alliaceous odor, and was obtained as a 
 cream colored waxy solid. 
 
 The operation was performed with a solution con- 
 sisting of three parts of ordinary concentrated sul- 
 phuric acid, and four parts of water. The solution 
 was brought to its boiling point in a flask connected 
 with a condenser and a receiver, while the two gases 
 previously mixed were passed into the acid. The 
 addition of a few grams of mercuric oxide to the 
 
- 15 - 
 
 solution, resulted in an increased yield ofthethio- 
 aldehyde. The mercuric oxide added to the solution 
 was first transformed into sulphate, and this in turn 
 was changed into sulphide, as indicated by its black 
 color. The thioaldehyde solidified in the upper part 
 of the condenser to its polymeric modification, trithio- 
 aldehyde. The gaseous products of the reaction, 
 when passed into strong ammonia water, formed a 
 cream colored precipitate mixed with sulphur, and 
 possessed an odor like that of acetamide and mer- 
 captan. Thioaldehyde and free sulphur were also 
 found in the distilling flask. 
 
 The formation of the free aldehyde may be ac- 
 counted for by reason of the catalytic action of the 
 mercury salt on the acetylene. It is not improbable 
 that an intermediate organic mercury compound of 
 acetylene is formed. The reactions may be repre- 
 sented as follows : 
 
 C 2 H 2 -|-H 2 S CH 3 CHS , 
 
 CH 3 . 
 
 The thioaldehyde may result by the action of the 
 hydrogen sulphide on the acetaldehyde obtained 
 from the action of the dilute sulphuric acid on acety- 
 lene in the presence of mercuric salts. 
 
 CH 3 CHO+H 2 S = CH 3 CHS+H 2 0. 
 Thus Weidenbusch 1 found that when hydrogen sul- 
 
 1 Ann. 66, 158. 
 
i6 
 
 phide is passed into an aqueous solution of acetalde- 
 hyde, thioaldehyde was obtained. 
 
 As I have obtained crotonaldehyde by the action of 
 strong sulphuric acid on acetylene that was generated 
 from calcium carbide, it is evident that the formation 
 of the crotonaldehyde is not due to vinyl haloid 
 impurities, as Zeisel 1 maintained. 
 
 In order if possible to throw some light on the 
 action of acetylene on sulphuric acid, some of the 
 derivatives of the latter were treated with acetylene. 
 It was thought that some analogous reaction might 
 be found to explain the varied behaviour of sulphuric 
 acid itself under different circumstances. 
 
 NITROSULPHONIC ACID AND ACETYLENE. 
 
 Nitrosulphonic acid did not react with acetylene 
 at ordinary temperatures. When the nitrosulphonic 
 acid was dissolved in pure monohydrate sulphuric 
 acid not better results were obtained. 
 
 Not only were no signs of reaction observed, but 
 the acetylene failed to react with the sulphuric acid, 
 with which it reacts very readily alone. Moreover the 
 gas after passing through the solution possessed an 
 ethereal odor as if it had been purified from the sul- 
 phur compounds that ordinarily give in its alliaceous 
 odor. 
 
 CHI^ORSUIvPHONIC ACID AND ACETYLENE. 
 
 Chlorsulphonic acid was found to absorb acetylene 
 very readily with the evolution of considerable heat. 
 The clear acid became dark-colored. When the 
 
 1 Ann. 19, 366. 
 
17 
 
 product was poured into water decomposition took 
 place quietly and a black, ill-sinelling, viscid mass 
 settled at the bottom of the vessel. Attempts to ob- 
 tain products pure enough for analysis did not suc- 
 ceed. When the product was distilled a few drops of 
 clear oil were obtained at a temperature of about 
 100 C., accompanied by decomposition with the 
 separation of carbon and hydrochloric acid. The oil 
 possessed the irritating odor and other characteristics 
 of allyl mustard oil. The oil was decomposed with 
 long continued contact with water. The study of the 
 reaction of acetylene with chlorsulphonic acid is 
 being continued in this laboratory. 
 
 REACTION OF ACETYLENE WITH SULPHUR TRIOXIDE. 
 
 Regnault, 1 in 1827, found that ethylene united 
 with the vapor of sulphur trioxide, and formed an 
 anhydride of an ethylene sulphonic acid. To the 
 
 CH 2 -S0 2 -0 
 compound was ascribed the formula, 
 
 CH 2 O SO 2 , 
 
 and it was called carbyl sulphate. With the anhy- 
 
 , CH 2 -S0 2 OH 
 dnde it gave rise to ethionic acid, 
 
 CH 2 O SO 2 OH, 
 
 and when this was boiled with water it broke down 
 
 CH 2 -OH 
 
 into isethiomc acid, and sulphuric acid. 
 
 CH 2 -SO 2 -OH, 
 
 From the investigation of Schroeter on the action of 
 acetylene with sulphuric acid, it became evident that 
 
 1 Ann. 25, 32. 
 Pogg. Ann. 
 
i 8 
 
 there is a perfect analogy between the sulphonic acids 
 of ethylene and acetylene. Hthionic acid corre- 
 sponds to the sulphate of acetaldehyde disulphonic 
 
 CH(SO 2 OH) 2 
 acid > Thls takm S U P water gives 
 
 rise to acetaldehyde disulphonic acid itself. 
 
 CH(S0 2 OH) 2 CH(S0 2 OH) 2 
 
 CH(0-S0 2 OH) 2 H 4+ CH(OH) 2 , 
 
 or, ^ SO ' H) * +H 2 0. 
 
 We should then expect that acetylene on account 
 of the greater chemical activity proper to its unsatur- 
 ated condition, would also form a compound with 
 sulphuric anhydride analogous to carbyl sulphate. 
 As acetylene has, however, two unsaturated bonds 
 more than ethylene, we may suppose the union of 
 acetylene to take place in two ways : 
 
 0-O 2 S-CH-SO-O 
 C 2 H 2 + 4 S0 8 _ 
 
 The first of these compounds is the anhydride of 
 acetaldehyde disulphonic acid, the second is the an- 
 hydride of the sulphate of acetaldehyde disulphonic 
 acid. Which of these is formed will be seen when ex- 
 amining the decomposition products of the compound 
 with water. 
 
19 
 
 In attempting the union of acetylene with sulphur 
 trioxide, the crystals from a strong solution of fuming 
 acid were used. These were quickly transferred to a 
 retort with a detachable neck. Some phosphorus 
 pentoxide was introduced into the retort with the 
 sulphur trioxide to insure complete dehydration. The 
 neck of the retort was inserted into a receiver cooled 
 with ice. Dry acetylene was passed into the receiver 
 until all the air was driven out of the apparatus, when 
 the sulphur trioxide was distilled from the retort by 
 gently heating the latter. 
 
 To insure thorough desiccation the acetylene was 
 passed through a wash-bottle containing sulphuric 
 acid, then through two drying cylinders filled with 
 pieces of calcium carbide and finally, through a long 
 tube of phosphorus pentoxide. The exit tube of the 
 retort, moreover, was connected with a cylinder of 
 fused calcium chloride so that in case air were 
 drawn into the apparatus by reason of the rapid ab- 
 sorption within, no moisture would be admitted. 
 
 When the acetylene came in contact with the vapor 
 of sulphur trioxide dense brown-colored fumes ap- 
 peared in the receiver, and some heat was evolved. 
 The acetylene had to be passed in very slowly to 
 prevent the union from taking place in the neck of 
 the retort, or even in the retort itself. 
 
 The product is a yellowish brown substance, at 
 first powdery and apparently amorphous, but soon 
 collecting on the sides of the receiver in ridges that 
 made the glass appear as if corrugated and gilded 
 within. Even under a 'magnifying power of 60 to 80 
 diameters no crystalline structure could be made out 
 
- 2O - 
 
 with the microscope. The product melted at a moder- 
 ate heat aiid simultaneously decomposed with the 
 separation of carbon and the appearance of acid 
 fumes. The compound was extremely deliquescent, 
 and in small quantity melted almost immediately on 
 exposure to moist air and changed to a dark brown 
 syrup. The decomposition product then possessed 
 the faint odor of garlic. Water could not be directly 
 added to the compound, as it decomposed completely 
 with a hissing noise, carbon being separated and sul- 
 phuric acid being formed. Sulphur dioxide was also 
 formed when the substance was decomposed with water. 
 The acid of this anhydride was obtained by exposing 
 the compound to moist air for a few days, thus allow- 
 ing it to absorb water very gradually. In this way 
 the anhydride was not completely broken down by 
 process of decomposition. After the substance had be- 
 come liquified, water was carefully added and the 
 barium salt obtained by neutralization with barium 
 hydroxide. The excess of the barium sulphate was 
 filtered off and the salt of the acid remained in the 
 solution. No methionic acid was obtained. Acetal- 
 dehyde disulphonic acid could not be obtained from 
 the solution by crystallization, nor could the oxime of 
 the same be prepared with hydroxylamine. The 
 solution contained only the barium sulphate of the 
 acetaldehyde disulphonic acid described by Schroeter. 
 He could not obtain it in condition for analysis owing 
 to the variation in composition of the salts. Schroeter 
 
 CH(S0 2 OH) 2 
 gave the add the formula, 
 
 The barium salt could not be crystallized from the 
 
- 21 - 
 
 solution and when heated almost to dryness on a 
 water bath, it solidified on cooling to a hard horny 
 brown mass which could be removed from the dish 
 only with great difficulty. It showed no definite 
 structure, and could not be crystallized from alcohol, 
 or ether, in either of which it did not seem to be ap- 
 preciably soluble. As no acetaldehyde disulphonic 
 acid or even methionic acid was obtained, but only 
 the sulphate of acetaldehyde disulphonic acid, it was 
 evident from the decomposition of the anhydride into 
 this sulphate, that the formula of the product of the 
 reaction of acetylene on sulphur trioxide is to be rep- 
 
 0-0 2 S-CH-S0 2 -0 2 
 represented, and not as 
 
 CH < 
 
 I ^2 
 
 CHO 
 
 The reaction of the decomposition of the anhydride 
 like that of the corresponding ethylene carbyl sul- 
 phate may be represented as follows : 
 
 CH 2 -S0 2 -0 CH 2 -S0 2 OH 
 
 CH 2 - O - S0 2 ' CH 2 -0-S0 2 OH, 
 
 +2HOH = 
 
 0-0 2 S-CH-S0 2 
 
 2 S-0- CH-O-SO^ 
 
 HO-0 2 S-CH-S0 2 OH CH(S0 2 OH) 2 
 
 HO-0 2 S-0-CH-0-S0 2 OH, r> CH(O-SO 2 OH) 2 . 
 
 All compounds of sulphuric acid and its derivatives 
 that have been discovered in the acetylene series can 
 be shown to be perfectly analogous to the correspond- 
 ing ethylene compounds. The compound of acety- 
 
- 22 
 
 lene with sulphur trioxide shows by its decomposi- 
 tion products that it possesses a constitutional formula 
 analogous to ethylene carbyl sulphate. The forma- 
 tion of these compounds is also similar. 
 
 O-O 2 S-CH-SO 2 -O 
 - ^ _ _c H _o-s6 2 . 
 
 Ethylene carbyl sulphate and water gives ethionic 
 acid, and boiled takes up another molecule of water 
 to form isethionic acid and sulphuric acid. l 
 
 CH 2 -S0 2 -0 CH 2 -S0 2 OH 
 
 CH 2 -0 - SO., "* CH 2 -0- S 
 
 2 S-0-CH-0-S0 2 CH(S0 2 OH) 2 
 
 6-O 2 S-CH-SO 2 -6 ~ CH 2 (O-SO a OH) 2 
 
 CH(S0 2 OH) 2 CH(S0 2 OH) 2 
 -CH(OH) 2 , r ' CHO+HOH 
 
 The reactions with acetylene and sulphuric acid 
 derivatives are more complicated than those of ethy- 
 lene as there are two additional valencies to be satis- 
 fied. As a consequence of loading down the mole- 
 cule decomposition into simpler derivatives is to be 
 expected whenever it seems possible to separate the 
 stabler elements of water and sulphuric acid. As is 
 
 1 Pogg. Ann. 47, 509. 
 
seen by comparing the foregoing reactions, cor- 
 responding to ethionic acid we have in the acetylene 
 
 ., CH(SO 2 OH) a , - , - 
 
 senes the which is men- 
 
 tioned by Schroeter 1 . Acetaldehyde disulphonic 
 acid, the decomposition product, is the acid cor- 
 responding to isethionic acid. It may be likely that 
 
 the formula of Muthman, CH(SO 2 OH) 2 may be ap . 
 
 CH(OH) 2 , 
 
 plied to it as it does not give up water even when at- 
 tempts were made to crystallize its salts over phos- 
 phorus pentoxide. Its salts of monovalent metals 
 contain one molecule of water and its salts of bival- 
 ent bases contain two molecules of water which can 
 not be separated without complete decomposition of 
 the compound. The formula of Schroeter also has 
 reasons for its application because of the property of 
 the acid to form an oxime and other derivatives char- 
 acteristic of aldehydes. As a further decomposition 
 product of both isethionic acid and acetaldehyde disul- 
 phonic acid we finally have methionic acid. 
 
 Bthylene when passed into fuming sulphuric acid 
 yields isethionic 2 acid directly, and acetylene under 
 the same conditions gives acetaldehyde disulphonic 
 acid. 
 
 When ordinary strong sulphuric acid or an acid 
 more or less hydra ted is used, none of the compounds 
 above mentioned is formed in appreciable quantity. 
 There is nevertheless reason to believe that here also 
 
 1 Ann. 303, 114. 
 
 2 Pogg. Ann. XI, VII, 509. 
 
2 4 - 
 
 the analogy of the formation of the analogous com- 
 pounds still holds true. 
 
 Faraday, l Hennel, Regnault and Magnus tried the 
 action of ethylene on sulphuric acid or its anhydride. 
 Hennel found that when ethylene is led into sul- 
 phuric acid ethyl sulphuric acid is formed. Berthelot 
 repeated the work of Hennel and obtained the same 
 results, namely ethyl sulphuric acid and alcohol. 
 
 When ordinary sulphuric acid is used the product 
 differs completely from that obtained by the action of 
 ethylene on an acid containing free sulphur trioxide, as 
 may be seen by comparing the formulas of the com- 
 pounds in question. Ordinary sulphuric acid with 
 ethylene gives ethyl sulphuric acid, a metamer of 
 isethionic acid. 
 
 Sulphuric Acid. Ethyl Sulphuric Acid. 
 
 HO SQ (C 2 H 5 )0 SQ 
 
 HQ >S0 2 , HO >S " 
 
 Isethionic Acid. 
 
 C 2 H 4 (OH) 
 
 H0 > U2> 
 
 Ethyl sulphuric acid, the product of the action of 
 ethylene on strong sulphuric acid gives alcohol or 
 ether when distilled, according to the conditions of 
 the experiment. 
 
 CH 2 , HO (C 2 H,)0 
 
 1 Philosophical Transactions, ( 1826) 240, ( 1828) 365. Ann. 
 Chim. Phys. XXX., 154, (1827). v See also Moniteur Scien- 
 tifique, 4 Ser. XVIII., p. 7, 15, 21. 
 
25 
 
 HO >S 2 
 
 Berthelot tried to obtain the alcohol of the acety- 
 lene series, vinyl alcohol. It was shown that the 
 principal, if not the only product of the action of 
 acetylene on sulphuric acid, is crotonaldehyde. The 
 crotonaklehyde is the result of the condensation of 
 two acetaldehyde residues. Though a number of 
 attempts have been made to isolate vinyl alcohol 1 at 
 different times, success has not as yet been met with. 
 As a matter of fact all reactions in which the compound 
 is to be expected from its well known derivatives, 
 not vinyl alcohol but acetaldehyde is obtained. Thus, 
 for example, Semmler 2 expected to obtain vinyl 
 alcohol from divinyl sulphide treated with silver hy- 
 droxide, but acetaldehyde resulted instead. 
 
 It seems that all the reactions looking to the for- 
 mation of vinyl alcohol really give acetaldehyde. 
 Rearrangement of the molecule takes place at the 
 moment of the reaction. If vinyl alcohol is really 
 the product formed when acetylene acts on sulphuric 
 acid, dilution of the acid is sufficient both to break 
 
 J Ann. Chim. Phys. (3), LXVII, 6, (1863). Ann. Chim. 
 Phys. (7), XVII, 29, 7, (1869). Ber. 22, 2863. Gaz. XXIX, 
 
 ( i ), 390- 
 2 Ann. 241, 113. 
 
26 
 
 up the compound and condense the acetaldehyde to 
 crotonaldehyde. How then are we to explain the 
 formation of the acetaldehyde and crotonaldehyde 
 from the point of view that the reactions of ethylene 
 and sulphuric acid derivatives and acetylene and its 
 derivatives are analogous? 
 
 The fact is that, whether vinyl sulphuric acid be 
 present in the action of acetylene on dilute or ordinary 
 concentrated acid, or some other compound be formed, 
 acetaldehyde or crotonaldehyde is obtained as the 
 final product. It has been generally supposed that 
 acetaldehyde simply takes up the elements of water, 
 but this is no explanation, and is in fact hardly likely. 
 Acetylene and water do not unite except in the 
 presence of some catalytic agent, such as mercury 
 salts, carbon or sulphuric acid. Two methods of ex- 
 planation present themselves. According to one of 
 these we may suppose the presence of vinyl sulphuric 
 acid, as Berthelot maintains, according to the 
 reaction : 
 
 C 2 H 2 + H - (CH 2 :CH)0 
 (CH 2 : 
 
 HO 
 
 HO SQ 
 H0 > U 2 , 
 
 (CH 2 :CHOH)=CH 3 CHO. 
 
 As vinyl alcohol can not exist as such, it under- 
 goes rearrangement of its molecule and acetaldehyde 
 is evolved in dilute solutions of acid. If the acid is 
 
_ /y "7 _ 
 
 strong the acetaldehyde is simultaneously polymer- 
 ized to crotonaldehyde : 
 
 CH 3 CHO + 
 
 CH H 8 CHO^CH 3 CH:CH CHO+H 2 O. 
 
 Whatever the nature of the hydration of acetylene 
 it is evident that warm diluted sulphuric acid per- 
 forms a sort of a catalytic action in the production of 
 aldehyde not unlike the action of aluminium chloride 
 in the chlorination of hydrocarbons. At low temper- 
 atures the definite compound of sulphuric acid and 
 water separates in crystals of the composition, 
 H 2 SO 4 .HOH, which melt at 10.5 C. It may also be 
 likely that this definite compound gives up the 
 hydrogen and the hydroxyl group to acetylene and 
 then takes up another molecule of water. When the 
 acid becomes of a. certain dilution acetaldehyde ceases 
 to be formed, and this fact would strengthen the 
 theory. When the acid contains little or no water 
 the elements of water are abstracted from two mole- 
 cules of acetaldehyde, and one molecule of crotonal- 
 dehyde results. The reactions may be represented 
 as follows : 
 
 = CH a :CHOH-pH a S0 4 , 
 CH 2 :CHOH = CH 3 CHO, 
 
 = H 2 SO 4 -H 2 O. 
 
 In case no water be present we would have the 
 reaction : 
 
 H 2 SO 4 'H 2 O. 
 
28 
 
 Pure monohydrate sulphuric acid reacts with acety- 
 lene like ordinary concentrated sulphuric acid, and 
 the product on dilution gives crotonaldehyde as the 
 principal product. 
 
 Other substances besides sulphuric acid possess the 
 power of acting as catalytic agents in oxydizing or 
 hydrating acetylene. Degrez 1 found that acetylene 
 is absorbed by carbon, and when this was heated with 
 water in closed tubes, acetaldehyde was obtained. 
 The salts of mercury produce the same result when 
 boiled in aqueous solution while a stream of acetylene 
 was passed into them. The yield of acetaldehyde 
 seems to be increased in the presence of free acid. 
 In the last case the evolution of the aldehyde is due 
 to the formation and subsequent decomposition of 
 vinyl or aldehyde derivatives containing mercury, as 
 will be shown more fully in another paper. These 
 mercury derivatives are the intermediate products. 
 Some have already been isolated and their formulas 
 determined with accuracy, others will be described in 
 a special article further on. 
 
 FORMATION OF ALDEHYDE FROM ACETYLENE IN PRESENCE 
 OF FINELY DIVIDED PLATINUM. 
 
 Finely divided platinum may also be used to cause 
 acetylene to take up the elements of water. When 
 acetylene is passed for some time into reduced plati- 
 num suspended in water acidified with dilute nitric 
 acid, aldehyde is formed. The product is allowed to 
 stand by itself for some time in order to permit all 
 the acetylene in solution to change into aldehyde. 
 
 1 Bull. Soc, Ch. XI, 362. 
 
- 29 
 
 The odor of the gas disappears and that of acetalde- 
 hyde becomes very noticeable. The product is filtered 
 and the filtrate treated with iodine and caustic potash 
 to an alkaline reaction when an abundant precipitate 
 of iodoform is obtained. When the suspended plati- 
 num is acidified with hydrochloric acid no aldehyde 
 is obtained. Similar results could not be obtained in 
 alkaline solutions in which reduced cobalt was sus- 
 pended. 
 
 Acetylene shows the general tendency to form 
 aldehyde derivatives and behaves like acetaldehyde 
 itself in many reactions. Towards sulphuric acid the 
 action of acetylene and acetaidehyde is exactly simi- 
 lar. Weidenbusch 1 first noticed that acetaldehyde 
 was absorbed by sulphuric acid, but he threw no light 
 on the nature of the reaction that takes place. He 
 simply stated that the acid. became dark-colored when 
 aldehyde was passed through it. 
 
 Delepine 2 found that ordinary aldehyde gave defi- 
 nite products with strong 'sulphuric acid. The latter 
 yielded as a product of reaction the same compounds 
 as were obtained by Schroeter by the action of acety- 
 lene on the acid under the same conditions. Acetal- 
 dehyde disulphouic acid and methionic acid were 
 obtained. With ordinary strong sulphuric acid 
 crotonaldehyde resulted on dilution of the product, 
 as Kekule had found before. This is likewise the 
 product obtained from the action of acetylene upon 
 sulphuric acid as L,agermarck and Kltekow, and 
 
 1 Ann. 66, 155. 
 
 2 Compt. Rend. 133, 875. 
 
- 3 o- 
 
 Zeisel have shown. Other derivatives of acetalde- 
 hyde, such as acetamide and chloral also give rise to 
 acetaldehyde disulphonic acid when treated with fum- 
 ing sulphuric acid. In summing up the results we 
 may conclude that the analogy of the reactions be- 
 tween acetylene and ethylene in their behaviour 
 towards sulphuric acid generally holds true. 
 
 i. Acetylene in dilute boiling solutions of sul- 
 phuric acid is oxydized to vinyl alcohol and this by 
 intramolecular rearrangement becomes acetaldehyde. 
 It is probable that a vinyl compound is first formed 
 which being very unstable breaks down into the 
 other compounds just mentioned. 
 
 2. In the presence of strong sulphuric the acet- 
 aldehyde supposed to be formed is condensed to 
 crotonaldehyde with the separation of water ; ordinary 
 alcohol heated with concentrated sulphuric acid also 
 loses water and is changed to ether. 
 
 3. With fuming sulphuric acid the derivatives of 
 acetylene are perfectly analogous to those of ethylene, 
 being the sulphonic acids of ethylene and acetylene 
 as already mentioned. 
 
 4. Sulphur trioxide gives an anhydride with acety- 
 lene similar to the ethylene compound. It decom- 
 poses with the addition of water into the sulphate of 
 acetaldehyde disulphonic acid, which is analogous to 
 ethionic acid in the ethylene series. Further decom- 
 position changes this sulphate into acetaldehyde 
 disulphonic acid which is analogous to isethionic acid 
 the compound similarily obtained from ethionic acid. 
 
 f 
 
THE ACTION OF SULPHURIC ACID ON CALCIUM 
 CARBIDE 
 
 The behaviour of sulphuric acid toward calcium 
 carbide varies according to the conditions under which 
 the experiment is carried on, such as temperature of 
 the operation, the strength of the acid used, and the 
 degree of fineness of the calcium carbide employed. 
 Dilute sulphuric acid differs little in its action on 
 carbide from water. The water present decomposes 
 the carbide and calcium sulphate results by the 
 further action of the acid. 
 
 i. Whenever the action of a compound with cal- 
 cium carbide is very rapid much heat is given off by 
 reason of the endothermic nature of the compound 
 and very often total decomposition takes place. 
 When concentrated sulphuric acid is allowed to drop 
 on pieces of calcium carbide the size of a pea, or when 
 powdered carbide be thrown into strong sulphuric 
 acid this total decomposition takes place without the 
 application of external heat. In general when finely 
 divided carbide is used the breaking down of the acid 
 and the separation of carbon can only be prevented 
 by cooling the acid in a freezing mixture or throwing 
 pieces of ice into the acid. 
 
 In an experiment performed a flask of five 
 litres capacity was used and a mixture of about 
 one hundred grams of granulated and powdered 
 calcium carbide was put into it. From a drop- 
 ping funnel strong sulphuric acid was allowed 
 to fall upon the mixture. The first drop caused a 
 strong evolution of vapors, the violence of the reac- 
 tion increasing as more heat was evolved. The gases 
 
-32- 
 
 were passed through a well cooled receiver. The 
 mass of the carbide became brown, and finally much 
 carbon separated. Sulphur dioxide, hydrogen sul- 
 phide, acetylene and carbon dioxide were given off. 
 By far the greater portion of the gas consisted of 
 sulphur dioxide and acetylene. Hydrogen sulphide 
 was present in great quantity, especially at the be- 
 ginning of the operation and later on it ceased to be 
 formed. I^ead acetate gave at first a black precipitate 
 of the sulphide but later only the sulphite was ob- 
 tained. The acetylene was determined by absorption 
 with silver nitrate in ammoniacal solution. The 
 residue in the flask consisted of a dirty black mass 
 composed principally of calcium and magnesium sul- 
 phates and carbon. When the decomposition was 
 carried on while heating the acid in the flask and 
 allowing calcium carbide slowly to fall into the acid 
 the action was more violent but no different results 
 were obtained. 
 
 2. Powdered and granulated carbide was added to 
 strong sulphuric acid cooled in ice-water. Decom- 
 position took place slowly and the action could not 
 be well regulated. Acetylene was evolved with some 
 hydrogen sulphide, sulphur dioxide came off when 
 the action became uncontrollable. Constant stirring 
 was necessary to prevent this complete decomposition 
 with the evolution of sulphur dioxide. The mass did 
 not become brown but calcium sulphate was precipi- 
 tated and the mixture became a pasty consistency. 
 The odor of hydrogen sulphide was only noticed after 
 standing for some days. Neither aldehyde or croton- 
 aldehyde could be noticed. The characteristic odor 
 
-33- 
 
 of thioaldehyde was present when the mixture was 
 diluted. 
 
 3. When acid more dilute was used, for example, 
 of specific gravity 1.75, or when strong acid was 
 allowed to stand uncovered so that moisture could be 
 absorbed from the atmosphere, a precipitate soon 
 occurred, decomposition took place slowly, and hydro- 
 gen sulphide was evolved with the acetylene. After a 
 few days the strong odor of thioaldehyde was noticed. 
 The thick emulsion was somewhat diluted with water, 
 put into a large flask and carefully heated to the 
 boiling point. The distillate contained not even traces 
 of either acetaldehyde or crotonaldehyde. The thioal- 
 dehyde heated in an acid solution was polymerized to 
 parathioaldehyde which was precipitated as a yellow 
 waxen mass in the cooler parts of the condenser. 
 The thioaldehyde was supposed to result either from 
 the action of the nascent acetylene on hydrogen sul- 
 phide, or from the action of hydrogen sulphide on 
 ordinary aldehyde. A mixture of iron sulphide and 
 carbide gave an increased yield of the thioaldehyde 
 when treated with acid of the same concentration. 
 
 In the experiments just described the solu- 
 tion was carefully examined for organic salts. 
 Only the faintest traces of formic acid were found. 
 Magnesium sulphate was found in quantity, neither 
 acetaldehyde disulphonic acid or methionic acid could 
 be detected in their salts, nor any of the compounds 
 mentioned by Schroeter. To make sure that none of 
 these products if present might escape observation, 
 the calcium salts of the filtrate were changed into 
 the barium zinc and other metallic compounds but 
 
- 34 
 
 no organic substances were found in appreciable 
 quantity, though large amounts of material were re- 
 peatedly employed. The magnesium sulphate was 
 mixed with some tarry impurities when evaporated 
 to dryness but even here only traces of organic mat- 
 ter were shown by ignition. Repetitions of these 
 attempts gave the same results ; a trace of formic 
 acid and parathioaldehyde. 
 
 4. The action of calcium carbide on stronger acid 
 of specific gravity 1.82 to 1.84 gave by slow action 
 quite different results at ordinary temperatures. 
 Four or five liters of this acid were poured into a 
 beaker and several large pieces of calcium carbide 
 were immersed in the acid so as to be completely 
 covered. The beaker was placed in a stronger ves- 
 sel to guard against the evil results of breakage, and 
 was carefully covered to prevent the absorption of 
 water from the atmosphere. The action was very 
 slow, and in winter weather would continue a month 
 before evident results could be obtained from a test- 
 portion diluted with water. In the summer and in 
 direct sunlight a few days were sufficient to bring out 
 decided results and the acid began to take on a choco- 
 late color. At first the carbide steadily gave off 
 small bubbles, and a faint sweet smell mixed with the 
 odor of sulphur dioxide was evolved. For some time 
 the calcium carbide presented a clean surface to the 
 acid as the calcium sulphate was dissolved to a clear 
 solution. On the whole the evolution of gas was ex- 
 tremely slow. After a while the excess of sulphate 
 could no longer be held in solution and the acid be- 
 came viscid and muddy. During the process the 
 
35 
 
 solution was frequently stirred, yet care had to be 
 taken not to move about the pieces of carbide too 
 violently as a series of surface explosions occurred 
 when the carbide was rubbed gently with a glass 
 rod These small detonations were like the explos- 
 ion of a percussion cap and were accompanied with 
 the appearance of a flash of bright light. A gas was 
 given off which on coming in contact with the air 
 gave a small cloud of smoke. When the carbide was 
 moved over the bottom of the vessel a continuous 
 rattle of these minute explosions was obtained and 
 the flash of flame was at times two centimeters in 
 length. This phenomenon occurred as long as the 
 surface of the carbide was kept from the sediment of 
 calcium sulphate. The explosions did not occur on 
 the whole surface of the carbide, but principally at 
 metallic looking nodules. Sharp edges gave the 
 explosions very energetically. The phenomenon 
 might be due to minute pieces of free calcium, to cal- 
 cium phosphide giving off phosphine, or to silicon 
 compounds giving off silicon hydride. The explos- 
 ions never occurred unless the carbide was rubbed or 
 moved. They have not been known to take place 
 spontaneously. 
 
 When the pasty mass, the product of the experi- 
 ment just referred to, was poured into cold water, 
 the strong odor of crotonaldehyde was given off and 
 calcium sulphate was immediately precipitated. Up- 
 on subjecting the decomposed mixture to distillation, 
 vapors passed over with some water at a temperature 
 below 100 C. The distillate possessed the odor and 
 the other characteristics of crotonaldehyde as described 
 
-36- 
 
 by Kekule 1 . The crotonaldehyde was oxydized to 
 crotonic acid by means of silver hydroxide. A bright 
 silver mirror was obtained acccording to the reaction : 
 
 2 CH 3 CH:CHCHO+3Ag 2 = 
 2CH 8 CH: CHCOOAg+H 2 0+ 4 Ag. 
 
 After filtering off the excess of the silver oxide, 
 the solution was heated on a hot water bath to obtain 
 the silver salt, but decomposition set in. The vapors 
 evolved possessed a rancid odor and a dark-colored 
 precipitate was left in rings on the dish as the water 
 evaporated. As the silver salt could not be obtained 
 it was changed into the barium salt with barium car- 
 bonate. The barium salt crystallized from water in 
 small cubes. 
 
 Part of the distillate was treated with sodium car- 
 bonate and iodine and on warming an abundant pre- 
 cipitate of iodoform was obtained. The crystals were 
 filtered and their melting point found to be 119 C. 
 The product was pure iodoform. Reduction with 
 zinc dust gave the nauseating odor of butyric 
 alcohol. 
 
 5. Monohydrated sulphuric acid was also treated 
 with calcium carbide in the same manner as 
 described for sulphuric acid. The action was more 
 rapid, and cooling had to be applied to prevent com- 
 plete decomposition of the acid. In a few hours the 
 action was almost completed. The acid became so 
 pasty that the contents could not be poured from the 
 vessel. Similar results were obtained as in the pre- 
 ceding experiment, but the yield of crotonaldehyde 
 
 1 Ann. 162, et Seq. 
 
OF THE 
 
 UNIVERSITY } 
 37 F 
 
 ^jLTTiRK '.>/ 
 
 was much better in proportion to the amount of the 
 acid used. 
 
 ELECTROLYSIS OF VARIOUS SOLUTIONS WITH CAL- 
 CIUM CARBIDE ELECTRODES. 
 
 Before entering upon the course of experiments, I 
 shall detail some of the methods used in the analysis 
 of the gaseous products, as most attention was paid 
 to the volatile products that were formed. Consid- 
 erable difficulty was experienced in the separation 
 and analysis of the gases formed. Though it is easy 
 to obtain absorbents for the individual gases, their 
 complete elimination and separation is in some cases 
 a very tedious operation, and often the separation 
 volumetrically was found to be impossible. 
 
 Ammoniacal cuprous chloride has been used as an 
 absorbent for acetylene, but as it dissolves indefinite 
 amounts of ethylene according to the concentration 
 of the solution of the absorbent, it can not be used 
 without modification of the method. The separation 
 of acetylene from sulphur gases is very difficult vol- 
 umetrically. No absorbent has been found that will 
 perfectly and quickly separate sulphur gases without 
 affecting the ethylene and acetylene present. The 
 method of Berge and Reychler 1 for the purification of 
 the acetylene though it may remove all phosphine, 
 nevertheless dissolves large amounts of the hydro- 
 carbon with the formation of definite mercury com- 
 pounds. The authors claim that the solution can be 
 used for quantitative separation of the gases, and 
 
 Soc. Chim. Ill, XVII, 218, (1897). 
 
-38- 
 
 recommend a solution consisting of eighty parts of 
 water, twenty of hydrochloric acid and eight of mer- 
 curic chloride. The gas is first passed through caus- 
 tic potash, where the sulphur gases and carbon 
 dioxide are removed. Hydrogen sulphide is changed 
 to sulphate in the potash solution. Phosphorus is 
 changed to phosphate and determined gravimetrically 
 by the method of Sonnenschein. I have tested the 
 purifying agent of Berge and Reychler to see if it 
 could be used volumetrically, but negative results 
 were obtained. In the first place hydrogen sulphide 
 is not perfectly absorbed by caustic potash as was 
 found by test experiments on known volumes of 
 gases. Moreover, the potash solution holds acetylene 
 gas in solution in varying proportions according to 
 the concentration. If the caustic solution be previ- 
 ously saturated with acetylene the difficulty is not 
 overcome. Unreliable variations occur. Lead acet- 
 ate will take up all the hydrogen sulphide, but acet- 
 ylene is also absorbed, and the quantities taken up 
 vary. 
 
 Although the absorbent of Berge and Reychler does 
 not precipitate acetylene the gas is nevertheless dis- 
 solved with the formation of definite compounds, as 
 was shown by Biginelli. 1 I have found that ninety- 
 five per cent, of the gas is taken up by the reagent. 
 It can not then be used in the Hempel absorption 
 apparatus. If the solution be previously saturated 
 with the gas, the absorbent can not be relied on as it 
 gives erratic results. It has accordingly been found 
 
 1 Ann. di Farm, e Chim. (1898 ), 16. Cent. ( 1898 ), 925. 
 
- 39- 
 
 necessary to omit the elimination of the phosphine. 
 At all events the traces are quite faint and would not 
 tend to influence the results of the experiments 
 appreciably. 
 
 The various constituents of the gaseous product 
 were successively taken out by their proper absorbents 
 and the apparatus used for the analysis was of the 
 type introduced by Hempel For the elimination of 
 the acetylene, however, the Bunte-Seger apparatus 
 was used in connection with the Hempel burettes and 
 pipettes. 
 
 The substances liable to be met with in this work 
 are somewhat limited and consist principally of 
 acetylene, ethylene, ethane, oxygen, carbon dioxide 
 and carbon monoxide, traces of sulphur dioxide and 
 hydrogen sulphide. Ammonia and oxides of nitro- 
 gen are to be met with. Sulphur dioxide was 
 generally found in such small quantities as to be neg- 
 ligible. The gas mixture was in every case left to 
 stand over water for some time in order to allow 
 gases soluble in water to be taken out. Acetylene 
 was in every instance taken out first because of the 
 quantity present and because it is taken in solution 
 by nearly all of the other absorbents in greater or less 
 degree. The absorption was made by the method 
 described by Moody and Tucker. 2 The authors found 
 that an ammoniacal solution of silver salt is the best 
 absorbent for separating acetylene from ethylene 
 volumetrically. To a solution of silver nitrate hydro- 
 chloric acid is added until an acid reaction is obtained. 
 
 'Jour. Amer. Chem. Soc. 23, 671. 
 
- 40- 
 
 Ammouia water is then added until the reaction is 
 just alkaline. This was found to be a better solution 
 than arnmonical cuprous chloride which absorbs large 
 quantities of ethylene. The gas can be regained, 
 however, on boiling the cuprous chloride solution as 
 Berthelot 1 described but the method is longer and 
 more tedious. I have examined Moody and Tucker's 
 reagent with known mixtures of the two gases. 
 Though it is not as sensitive to small quantities of 
 acetylene as ammoniacal cuprous chloride, and though 
 the last traces of the gas can be eliminated only after 
 a long absorption, the use of the Bunte-Seger appar- 
 atus effects the completion of the operation in a very 
 short time. 
 
 The ethylene is separated in the usual manner over 
 fuming sulphuric acid containing crystals of sulphur 
 trioxide. Hydrogen was taken out by means of 
 palladium as described in the manuals of gas analysis. 
 The ethane was determined by explosion after the 
 hydrogen had been removed. It was also calculated 
 by silent combustion in a Winckler's pipette with 
 incandescent platinum spiral. Of the anode products 
 carbon dioxide was quickly removed in the caustic 
 potash pipette. Acetylene was next taken out and 
 then oxygen with the phosphorus pipette. 
 
 ELECTROLYSIS OF SULPHURIC ACID WITH CALCIUM CARBIDE 
 
 ELECTRODES. 
 (PRELIMINARY EXPERIMENT.) 
 
 Before the operation described by Harris 2 had come 
 
 1 Ann. Chim. Phys. 3, LXVII, 57, ( 1863 ). 
 
 2 Electrochemical Industry, p. 131, (Vol. i. ) No. 4, (Dec. 
 1902 ). 
 
4 1 
 
 to my notice experiments somewhat similar had al- 
 ready been made in this laboratory. The object of 
 the work was to effect results such as those mentioned 
 by the author, namely to obtain alcohol or ether from 
 acetylene by means of electrolysis. Instead, how- 
 ever, of passing acetylene into heated sulphuric acid, 
 one or two soluble electrodes of calcium carbide were 
 used. At the carbide cathode the hydrogen ions 
 would come in contact with nascent acetylene slowly 
 given off by the electrode which reacted with the 
 acid or rather with the water in the sulphuric acid. 
 The first experiment was conducted with no other 
 end than to obtain qualitative results. It was ex- 
 pected that the ethylene uniting with the sulphuric 
 acid would form ethyl sulphuric acid and that ether 
 or alcohol would be obtained from this on diluting or 
 distilling the product. The distillate gave the iodo- 
 form test unmistakably, in fact it was possible to ob- 
 tain considerable quantities of the latter compound. 
 To be sure that the iodoform was really due to alco- 
 hol, the experiments already referred to, or the action 
 of acetylene on sulphuric acid, were undertaken. It 
 was found that iodoform was obtained even when no 
 current had been used, both when acetylene was 
 allowed to act on sulphuric acid, and when calcium 
 carbide was allowed to react with stronger sulphuric 
 acid. As, however, the iodoform test does not prove 
 conclusively the presence of alcohol, it will be neces- 
 sary to obtain and analyze alcohol as such. If the 
 ethylene which is present previous to the formation 
 of ethyl sulphuric acid, be collected and analyzed, we 
 may conclude that the iodoform test was obtained at 
 
-42- 
 
 least partly from the alcohol that was formed. 
 
 Principally the gaseous products of the experiments 
 will be examined in order to arrive at definite con- 
 clusions as to the presence of alohol. I shall now 
 describe some of the experiments performed in the 
 electrolysis of sulphuric acid with calcium carbide 
 electrodes. 
 
 In the preliminary experiments the apparatus used 
 is represented in figure ( i ). A well-shaped piece of cal- 
 cium carbide was chosen for each electrode. A hole 
 about one half a centimeter in diameter was bored 
 into one end with a steel drill, and a copper wire was 
 fastened into this with melted lead. The electrodes 
 were contained in porous cups in order to examine 
 separately the products of reaction at each pole. 
 Each porous cup was closed with a stopper through 
 which a Wurtz tube was passed. The electrical con- 
 nections with the poles were made through the corks 
 of the Wurtz tubes, while the gas was conducted 
 through the side tubes into separate gasometers. 
 The electrodes dipped only partly below the surface 
 of the acid in each cup, and the operation of elec- 
 trolysis was carried on in a large thick walled vessel. 
 The thermometer in the vessel registered the tem- 
 perature during the experiment. 
 
 In dilute solutions of sulphuric acid acetaldehyde 
 is present at least when heated. At the anode simul- 
 taneously with the oxidation of acetylene to carbon 
 dioxide and water, aldehydes might become acids. 
 At the cathode, reduction of aldehyde would take 
 place to form alcohol. Acetylene might likewise be 
 changed to ethylene with the subsequent formation 
 
43 
 
-44- 
 
 of ethyl sulphuric acid. It remains then to be found 
 out whether the actual results in the experiments to 
 be described correspond to the expectations enter- 
 tained in regard to the formation of the compounds 
 enumerated. 
 
 Calcium carbide has been found to conduct elec- 
 tricity to a considerable extent, though compared to 
 the metals it has a low conductivity. This great 
 resistance to the current is one of the principal diffi- 
 culties to be contended with in using this substance 
 as an electrode. Owing to the great electromotive 
 force that must be used, the calcium carbide becomes 
 very much heated. If the contact is not very good 
 the copper wires at this point are often melted. 
 
 In cold concentrated aqueous solutions of some 
 salts, calcium carbide is very stable. Concentrated 
 sulphuric acid attacks it very slowly, and it is gen- 
 erally necessary to add water in order to increase the 
 evolution of gas. Concentrated calcium chloride and 
 calcium nitrate solution are almost without any 
 action upon calcium carbide, and must in neutral 
 solution be diluted with even more water than sul- 
 phuric acid. Zinc chloride and sodium hyposulphite 
 must also be diluted when concentrated solutions are 
 used. It was thought advisable to use these solu- 
 tions of salts in order to obtain decisive results as to 
 the presence of ethylene, in the electrolysis of elec- 
 trolytes with calcium carbide cathode. 
 
 I have already referred to electrolysis in the 
 presence of acetylene gas in solution in the electro- 
 lyte. I have not been able to find that any attempt 
 was made to use calcium carbide as a soluble electrode 
 
45 - 
 
 giving off nascent acetylene. We should expect that 
 if an electrolytic synthesis were likely to take place 
 it ought to occur where the constituents are present 
 in the nascent state. If hydrogen unites to acetylene 
 to form ethylene, as Wilde and Berthelot have shown, 
 we should expect the same result at the cathode of 
 calcium carbide. The ethylene thus formed in sul- 
 phuric acid solution would unite with the acid to form 
 ethyl sulphuric acid. This at the proper temperature 
 would give off ether and alcohol according to the 
 conditions of dilution or concentration. It would be 
 simply necessary to maintain in the solution of acid 
 the proper proportion of water. The action was ex- 
 pected to take place as follows : 
 
 4 * H 2 = CaSO 4 + C 2 H 2 + H 2 O, 
 
 H 2 SO 4 =2H-fSO 4 , or H+HSO 4 , 
 
 During the subsequent experiments the current 
 used in the electrolysis was obtained from a storage 
 battery of fifty cells. A voltmeter and amperemeter 
 registered accurately the constants of the current. 
 For the experiment in question an electromotive force 
 
- 4 6- 
 
 of one hundred volts was used. The electrolyte was 
 ordinary concentrated sulphuric acid somewhat dilut- 
 ed during the experiment in order to obtain a suit- 
 able flow of gas before turning on the current. On 
 turning on the switch an immediate increase of the 
 flow of gas was noted. After the operation had been 
 allowed to continue for some time to drive the air out 
 of the apparatus, and also to obtain normal condi- 
 tions of experiment, the gas was collected in separ- 
 ate gasometers from both poles simultaneously. The 
 reaction was continued for more than three hours, 
 during which a considerable rise of temperature 
 occurred, and the acid began to take on a brown 
 color both in the cups and in the solution outside of 
 the cups. The average temperature was noted at 
 different stages of the operation. The greatest rise 
 was noted in the path of the current, being about 70 
 to 71 C. 
 
 Sulphur dioxide was given off in small quantity as 
 the acid was decomposed. This occurred principally 
 at the cathode where the reduction takes place. After 
 the experiment the cathode was found to be very 
 little changed, though covered with a dark slimy 
 sediment. The anode was blackened and eaten away, 
 as if the acetylene had been completely decomposed 
 with the separation of carbon. After standing for 
 some time the contents of the porous cups were 
 separately analyzed, and the gases from the separate 
 poles were examined. Of the 56.6 ccm. of the gas 
 obtained at the anode only 7 ccm. were found to be 
 acetylene. No ethylene resulted. No trace of alco- 
 hol or ether was found. On decomposing the con- 
 
47- 
 
 tents of the porous cups with water an ethereal odor 
 was noticed, and when the product was distilled a 
 volatile compound passed over with water vapor be- 
 fore the thermometer registered 100 C. The distillate 
 possessed the odor of crotonaldehyde, and gave a 
 voluminous precipitate of iodoforin with sodium car- 
 bonate and iodine. The product showed all the 
 characteristics of crotonaldehyde. It was oxidized to 
 crotonic acid by freshly precipitated silver oxide. A 
 salt was obtained that could not be evaporated on the 
 water bath without decomposition. During the 
 breaking down of the compound the fumes given off 
 possessed the rancid odor of butyric acid. The iodo- 
 forrn obtained was filtered, dried and purified by 
 crystallization. It melted at U9C. exactly. Con- 
 sidering the small amount of acid decomposed the 
 yield of iodoform was considerable. The mirror test 
 for aldehyde was also obtained. It would be incon- 
 clusive to maintain that the iodoform test was due to 
 tha presence of alcohol since the product of distillation 
 gave an aldehyde reaction and possessed none of the 
 other characteristics of ethyl alcohol. Moreover as 
 L,ieben has shown aldehydes give the iodoform reac- 
 tion far more readily than ethyl alcohol. As the 
 gaseous product gave no trace of ethylene it seemed 
 evident that the current might not have effected the 
 union of nascent hydrogen with nascent acetylene. In 
 order to establish with certainty whether acetylene 
 could be united with nascent hydrogen at the cathode 
 of calcium carbide an extended series of experiments 
 was undertaken with various electrolytes with which 
 ethylene does not form a compound. If the product 
 
- 4 8- 
 
 of the electrolysis of dissolved acetylene in sulphuric 
 acid solutions be really alcohol then by using an 
 electrolyte that does not absorb ethylene the gas can 
 be estimated volumetrically by the methods of gas 
 analysis. 
 
 ELECTROLYSIS OF DILUTE SULPHURIC ACID WITH CALCIUM 
 CARBIDE ELECTRODES. 
 
 As dilute sulphuric acid does not readily absorb 
 ethylene attempts were made to obtain the free gas 
 by electrolyzing the dilute acid. In performing the 
 operation some difficulty was experienced. When 
 the acid was too dilute the carbide was rapidly eaten 
 away and a layer of calcium sulphate was formed on 
 the surface of the electrode. This acted as an insulator 
 or retarded the passage of the current. When on the 
 contrary the acid was too strong little or no acetylene 
 was given off. Water was constantly being used up 
 to cause a steady evolution of acetylene, and accord- 
 ingly it was difficult to keep a constant concentration 
 of acid. 
 
 The apparatus used in this experiment is repre- 
 sented in figure ( 2 ) . The electrolyte was a ten per 
 cent, solution of ordinary concentrated sulphuric acid. 
 The specific gravity of the acid at the beginning of 
 the operation was 1.09 at 33 C. An ordinary thick- 
 walled gas-cylinder was used as an electrolyzing 
 vessel. Contact at the cathode of calcium carbide 
 was made by means of a mercury connection. A bent 
 glass tube within which was a copper wire served to 
 connect the mercury at the bottom of the vessel with 
 the battery. The chloroform was gently poured upon 
 
49 
 
50 
 
 the mercury to the height of several centimeters, and 
 served to insulate the mercury from the electrolyte. 
 A shapely piece of calcium carbide was then floated 
 upon the mercury so as to present a large surface to 
 the electrolyte. The acid was the introduced and the 
 electrolysis was begun, using a platinum anode. The 
 gasometer was filled with water to the connection 
 ( B ) . The siphon ( D ) was also completely filled 
 with water. A funnel connection with a tube bent 
 at right angles, was placed so as to connect all the 
 evolved gases, and after the current had passed for 
 some time to allow the air to be driven from the fun- 
 nel, the connection was made at ( B ) and the gases 
 drawn into the gasometer by regulating the overflow 
 of water from the siphon at (D). Without much 
 careful manipulation the gas could be collected as fast 
 as it was given off. When sufficient gas has been 
 collected at the cathode of carbide the operation was 
 interrupted and the products analyzed. 
 
 The conditions of the experiment are given below. 
 
 TEMPERATURE. 
 
 CURRENT. 
 
 TOTAL GAS 
 EXAMINED. 
 
 ACETYLENE 
 FOUND. 
 
 ETHYLENE 
 FOUND. 
 
 RESIDUE. 
 
 I. 21 C. 
 
 2.2 5 
 
 Amp. 
 
 95. ccm. 
 
 25.8 ccm. 
 28 per ct. 
 
 3.2 ccm. 
 3 per ct. 
 
 64. ccm. 
 68. 5 per ct 
 
 SECOND SERIES OF EXPERIMENTS WITH DILUTE SULPHURIC 
 ACID. 
 
 A solution containing equal parts of strong sul- 
 phuric acid of the specific gravify 11.83, an( ^ f 
 water, was electrolyzed in an apparatus as shown in 
 figure ( 3 ). The specific gravity of the diluted acid 
 used as an electrolyte was 1.479 at 4 C. 
 
 A calcium carbide cathode was used. A piece of 
 
FIG. 3 
 
calcium carbide was shaped as shown in the illustra- 
 tion, having a large head and a cylindrical projection. 
 Many coils of fine copper wire were wound around 
 the cylindrical end, thus connecting it with a larger 
 copper wire bent like a fish-hook. A piece of thick 
 rubber tubing served to insulate the copper wires 
 from the solution so that the electrical connection 
 with the electrolyte was obtained only at the globular 
 end of the calcium carbide electrode. Mercury was 
 poured into the rubber tube in order to obtain a more 
 perfect connection. A platinum anode was used. 
 The gas was collected in an inverted Mohr burette 
 into which the electrolyte was drawn to the stop- 
 cock (E). In order that no bubbles of gas might be 
 lost, a funnel was held under the burette by means 
 of a bent glass rod fastened at ( B ) with a rubber 
 band. 
 
 The cathode was introduced into the solution, but 
 no gas was collected until the current had become 
 normal as shown by the voltmeter and amperemeter. 
 The electrode was then put under the funnel and the 
 duration of the experiment carefully recorded by 
 means of a stop-watch . All variations in the current 
 were also noted by the voltmeter and amperemeter, 
 and recorded as they occurred. When the burette 
 whose capacity was about fifty to sixty cubic centi- 
 meters, was filled, the operation was interrupted and 
 the gas transferred to a Hempel burette. Its volume 
 was then recorded and the gas subjected to analysis. 
 Acetylene was taken out with ammoniacal silver 
 solution in the Bunte-Seger burette, as this is espe- 
 cially adapted for shaking the gas with the absorbent. 
 
53 
 
 In experiment ( 2 ) a piece of muslin was tied about 
 the electrode in order to retard the reaction of the 
 dilute acid upon the calcium carbide and thus diminish 
 the amount of acetylene given out. In experi- 
 ments (4) and (5) a stronger acid, consisting 
 of one part of water and two parts of concentrated 
 acid was used. Experiments ( 4 ) and ( 5 ) record 
 the results obtained at an anode of calcium carbide. 
 During this operation great deviations in the strength 
 of current were noted. Beginning with 1.2 amp. a 
 sudden fall to .9 amp. occurred. Then came respect- 
 ively : .8, .7, .9, i.i amp., and again a sudden rise 
 was noted to 1.5, 1.6, 1.2, and 1.4 amp. 
 
 RESULTS OF THE EXPERIMENTS. 
 
 DURATION. 
 
 TEMPERATURE. 
 
 VOLTAGE. 
 
 AMPERAGE. 
 
 GAS COLLECTED 
 
 I. 90 Sec. 
 
 38 c. 
 
 50. 
 
 2-5-3 
 
 25.4 ccm. 
 
 II. 20 Min. 
 
 31 c. 
 
 20. 
 
 .5 ainp. 
 
 40.7 ccm. 
 
 III. 10 " 
 
 32 C. 
 
 51- 
 
 .6 amp. 
 
 45.2 ccm. 
 
 IV. 20 " 
 
 25 C. 
 
 2O. 
 
 .2-. 3. 
 
 18.4 ccin. 
 
 V.- 4 " 
 
 25 C. 
 
 TOO. 
 
 i.6-. 7 . 
 
 43 5 ccm. 
 
 GAS SOL. IN 
 WATER. 
 
 C 2 H 2 . 
 
 C 2 H 4 . 
 
 H 2 . 
 
 2 . 
 
 C0 2 . 
 
 CO. 
 
 RESIDUA!, 
 GAS. 
 
 I. 
 II. 
 
 III.-9.7 
 IV. 
 V. 
 
 54 
 4-2 
 
 2.7 
 12. 1 
 
 .2 
 .2 
 0. 
 
 13-7 
 
 1.8 
 i-7 
 
 i3-8 
 2.4 
 
 8.5 
 
 6. 02 ccm. 
 
 12.8 ccm. 
 4.8 ccm. 
 
 ELECTROLYSIS OF DILUTE SULPHURIC ACID WITH SLIGHT 
 PRESSURE. 
 
 The electrolysis of sulphuric acid accompanied with 
 pressure was performed in a Hoffman's apparatus as 
 shown in figure ( 4 ). Only slight pressure was here 
 obtained ; namely, that of the weight of the column 
 
54 
 
-55- 
 
 of acid about two feet in height. Pencils of calcium 
 carbide were used as electrodes. They were fastened 
 to the lower limbs of the apparatus by a piece of 
 strong soft rubber tubing, and well secured with 
 copper wires in order to prevent leakage of acid. The 
 electrical connections were made by mercury contact. 
 Two small beakers were filled with mercury, and the 
 exposed ends of the calcium carbide electrodes were 
 immersed in the metal beyond the rubber connection. 
 All action of air or of moisture was prevented on the 
 surface of the carbide. In order to wash away the 
 oxide from the calcium carbide it was washed with 
 alcoholic hydrochloric acid, and the alcohol was re- 
 moved with petroleum. The electrodes were wiped 
 dry with a cloth before the operation. The petroleum 
 oil extracted the alcohol from the electrode and the 
 white crystalline structure of calcium carbide was 
 brought out. When commercial calcium carbide was 
 allowed to remain for some days under petroleum, 
 many impurities were removed and the clear white 
 crystals of the compound could easily be observed. 
 Moissan first showed that chemically pure calcium 
 carbide consisted of these white or transparent 
 crystals. 
 
 When the electrodes were thus treated the action 
 of dilute sulphuric acid upon them was diminished. 
 No impurities were introduced into the subsequent 
 products of electrolysis as the oil consisted of saturated 
 hydrocarbons not acted upon during the operation. 
 The acid used in the electrolysis consisted of a mixture 
 of equal parts of strong commercial sulphuric acid 
 (Sp. Gr. 1.82), and distilled water. The current 
 
-56 
 
 was allowed to pass for some time before the gas was 
 collected. The anode and cathode gaseous products 
 were separately analyzed. 
 
 RESULTS OF THE EXPERIMENT. 
 
 
 TEMPERATURE. 
 
 VOLTAGE. 
 
 AMPERAGE. 
 
 GAS COLLECTED. 
 
 Anode. 
 Cathode. 
 
 18 - 28 C. 
 i8-28 C. 
 
 115. 
 115. 
 
 5 
 
 5 
 
 72.8 
 42.4 
 
 
 ACETYLENE. 
 
 ETHYLENE. 
 
 CARBON DIOXIDE. 
 
 Anode. 
 Cathode. 
 
 12.6 
 
 18.2 
 
 0. 
 
 29.7 
 
 ELECTROLYSIS OE CALCIUM HYDROXIDE SOLUTION WITH 
 CALCIUM CARBIDE ELECTRODES. 
 
 As calcium carbide was very quickly and violently 
 acted upon by water, or a dilute solution of calcium 
 hydroxide, some device had to be used to moderate 
 the action. The electrode was soaked for some time 
 in petroleum oil, or when this was not used the elec- 
 trode was covered with a piece of white muslin. 
 Precipitated calcium hydroxide did not insulate the 
 current as effectively as calcium sulphate. The 
 operation was performed with an apparatus as shown 
 in figure (3). Experiment (2) gave the results 
 obtained at an anode of calcium carbide. 
 
 RESULTS OF THE EXPERIMENTS. 
 
 DURATION. 
 
 TEMPERATURE. 
 
 VOLTAGE. 
 
 AMPERAGE. 
 
 GAS OBTAINED. 
 
 I. 80 Sec. 
 
 15 C. 
 
 20. 
 
 .6 
 
 54.8 ccm. 
 
 II. 243 Sec. 
 
 15 C. 
 
 53- 
 
 1.2 
 
 55.3 ccm. 
 
 III. - 63 Sec. 
 
 15 C. 
 
 53- 
 
 i-5 
 
 57.3 ccm. 
 
 IV. 124 Sec. 
 
 85 C. 
 
 53- 
 
 I.O 
 
 46.6 ccm. 
 
 V. 105 Sec. 
 
 93 C. 
 
 20. 
 
 3 
 
 39.4 ccm. 
 
57 
 
 GAS SOI,. IN 
 WATER. 
 
 C 2 H 2 . 
 
 C 2 H 4 . 
 
 Bv 
 
 2 . 
 
 C0 2 . 
 
 RESIDUAI, 
 GAS. 
 
 .8 
 9 
 i-5 
 
 466 
 42.8 
 42.5 
 27.4 
 31-5 
 
 4 
 
 .6 
 
 .8 
 
 2.0 
 
 3-8 
 
 4-4 
 4-5 
 2-3 
 
 4- 
 
 4. 
 
 4. ccm. 
 11.4 ccm. 
 9. ccm. 
 13. ccm. 
 2.1 ccm. 
 
 The precipitate of the electrolysis of calcium 
 hydroxide was analyzed, and a small quantity of car- 
 bonate was found to be present ; thus accounting for 
 lack of free carbon dioxide in the gas analysis of the 
 anode products. Oxalic acid was also detected as 
 calcium oxalate by the qualitative test. It was like- 
 wise determined by titration with a solution of 
 standard potassium permanganate. 
 
 ELECTROLYSIS OP CALCIUM CHLORIDE SOLUTION WITH 
 CALCIUM CARBIDE ELECTRODES. 
 
 The salts of calcium may be regarded as the typical 
 electrolytes for calcium carbide electrode. In an acid 
 solution the calcium of the carbide becomes a part of 
 the electrolyte as fast as it dissolves, and thus a 
 mixture of electrolytes is avoided. The soluble salts 
 of calcium give up water with great reluctance and 
 even deliquesce in their own water of crystallization. 
 It is easy to regulate the action of the solution of 
 such compounds upon the easily decomposed calcium 
 carbide. In order to obtain good results in the elec- 
 trolysis of these solutions, concentrated solutions can 
 not be used, as little or no acetylene is given off. It 
 is necessary to add water, or better to dilute the acid in 
 order to insure a sufficient evolution of acetylene. In 
 solutions of calcium chloride and calcium nitrate and 
 
- 5 8- 
 
 also of zinc nitrate, calcium carbide is practically 
 stable. If ethylene is formed it is not absorbed by 
 the electrolyte. Its presence can be decisively deter- 
 mined without relying on the iodoform test for alco- 
 hol when ethylene is calculated volumetrically. If 
 this gas can not be found in the products of electroly- 
 sis, it is justifiable to ascribe the iodoform precipitate 
 to aldehyde. If ethylene is not found it is most 
 probable that free alcohol was not present in the 
 products of electrolysis of solutions of sulphuric acid. 
 The object then is to determine whether sufficient 
 ethylene is formed to account for the precipitate of 
 iodoform obtained from the electrolysis of solutions 
 with calcium carbide electrodes. 
 
 In the experiments to be described the solutions of 
 calcium chloride was obtained by treating pure cal- 
 cium carbonate with hydrochloric acid. After filter- 
 ing the solution it was evaporated to a syrupy consist- 
 ency. It was not necessary to remove all the acid, as 
 this was afterwards added in order to insure a good 
 action at the surface of the electrode. From this 
 syrupy solution an electrolyte could be obtained 
 that attacks calcium carbide just fast enough 
 to insure a steady stream of acetylene while the 
 electrolysis is in operation. It was found best to add 
 hydrochloric acid rather than to dilute with much water 
 as strong acid solutions attacked calcium carbide 
 more readily than weaker aqueous solutions. The 
 acid served to keep the surface of the carbide elec- 
 trode free from precipitate of hydroxide or basic 
 insoluble products that acted as an insulator to the 
 current. A solution whose concentration corresponded 
 
-59- 
 
 to a specific gravity of 1.235, was found to be too 
 strong, for only forty bubbles of gas were obtained per 
 minute. It was further diluted until its specific 
 gravity of 1.2285 at 15.5 C. was denoted, and this 
 electrolyte was found to be best adapted for the 
 process of electrolysis at ordinary temperatures. 
 When the operation was carried at a temperature of 
 100 C. to 120 C. it was necessary to add more salt 
 in order to obtain a more concentrated solution. 
 
 1 . The electrolysis of a solution of calcium carbide 
 was first made with an anode of calcium carbide. A 
 current of one ampere to one and one-fourth amperes 
 was used, and an electromotive force of twenty volts. 
 A quiet evolution of gases took place for some time, 
 but after some minutes explosions occurred under 
 the liquid at the carbide anode. It was not consid- 
 ered safe to collect the gas in quantity owing to the 
 explosive nature of the product. A continuous vol- 
 ley of explosions and a display of sparks took place 
 at the electrode. When an attempt was made to col- 
 lect the gas in a test-tube the latter was shattered by 
 an explosion. Traces of tetrachloracetylene were 
 obtained in the electrolysis of calcium chloride with a 
 calcium carbide anode. 
 
 2. With the same current the cathode reactions 
 were studied. The apparatus used is shown in figure 
 ( 5 ). The cathode consisted of a large piece of cal- 
 cium carbide. A hole was bored into this and a 
 large copper wire fixed into it with fused lead. The 
 anode consisted of a piece of platinum foil and an 
 ordinary gas cylinder was used as a vessel for 
 electrolysis. To collect the gas a gasometer was at- 
 
6o 
 
tached as shown in figure ( 2 ). The entrance of the 
 gas was controlled by allowing water to flow from a 
 siphon which was regulated with a stop- cock (D). 
 The gas was collected at the electrode by means of a 
 wide-necked bottle, whose bottom had been removed. 
 The copper wire ( as shown in figure 5 ) that served 
 as a connection with the electrode was passed through 
 the cork of a Wiirtz tube and the gas carried off by 
 the side tube. The Wiirtz tube itself was fitted to 
 the bottle by a large rubber stopper. After contin- 
 uing the electrolysis for some time the gas was col- 
 lected and afterwards analyzed. When the experi- 
 ment was carried on too long the calcium chloride be- 
 came saturated with acetylene, and explosions took 
 place at the platinum anode. Of 101 ccm. of gas 
 collected, 88 ccrn. were acetylene and 1.6 ccm. were 
 absorbed over fuming sulphuric acid, corresponding 
 to ethylene. 
 
 3. The electrolysis of a solution of calcium 
 chloride at a temperature of 100 C. was tried in or- 
 der to ascertain if different results were obtained from 
 those resulting at ordinary temperatures. The appar- 
 atus used was shown in figure (3). Test experiments 
 were first made to find if explosions took place at the 
 anode in the heated solution. After some time it 
 was concluded that the operation could be carried on 
 with safety. 
 
 The temperature of the solution in this experiment 
 was 110 C. No explosion occurred with a current 
 strength of .5 amperes and a potential of 10 volts. 
 Again at a temperature of 1 16 C. and with a current 
 of 1.2 to 1.3 amperes and 20 volts, no explosions were 
 
62 
 
 observed. It was then thought safe to collect some 
 of the gaseous products. In the next attempt a cur- 
 rent strength of .5 amp. and 10 volts were used and 
 42.8 ccm. were collected in three minutes and five 
 seconds. No explosions occurred during the experi- 
 ment. On examining the gas, 40.2 ccm. were found 
 to be acetylene, thus showing that no free chlorine 
 gas had been obtained. Another operation was per- 
 formed with a current strength of i to 1. 1 amp. and 
 20 volts at a temperature of 112. To prevent accu- 
 mulation of gas bubbles on the carbide anode, a piece 
 of cloth was tied about it. The gas collected took 
 fire spontaneously in the burette with the separation 
 of carbon. About 31 ccm. of the residual gas were 
 passed into the Hempel burette. All but 18.8 ccm. 
 were absorbed by the water, showing it to be hydro- 
 chloric acid gas formed during the explosion. Of the 
 residue 13.8 ccm. were acetylene and neither oxygen 
 or carbon dioxide could be detected. 
 
 4. In the fourth experiment a calcium carbide 
 anode and a platinum cathode were used. With a 
 current strength of 20 volts and i.i amp., explosions 
 again resulted at the anode at ordinary temperatures. 
 A black deposit was left on the platinum cathode 
 This was insoluble in dilute or strong hydrochloric 
 acid and somewhat soluble in very strong nitric acid. 
 Heated on platinum no residue was left. It was con- 
 cluded that the deposit consisted of carbon electroly- 
 tically separated. Similar deposits of carbon at the 
 cathode have been obtained by various investigators. 
 
63- 
 
 ELECTROLYSIS OF ZINC CHLORIDE SOLUTION WITH CALCIUM 
 CARBIDE ELECTRODES. 
 
 Zinc chloride was electrolyzed under similar con- 
 ditions as already described in the electrolysis of 
 calcium chloride. The salt was prepared from 
 arsenic- free zinc with dilute hydrochloric acid. The 
 apparatus was of the type shown in figure (4). 
 After the solution had been evaporated to concentra- 
 tion, it was used as an electrolyte both at ordinary 
 temperatures and above 100 C. The solution was in 
 one of these operations boiled while the current was 
 passed through it. In the first experiment the anode 
 was a piece of calcium carbide and a zinc rod was 
 used as a cathode. An electromotive force of 20 volts 
 was applied, and this gave a varying current of 
 strength ranging as follows; (.1 amp., .6, 6.5, 4.5, 
 5, 5-5-6, 6.5, 6.6, 6.8, 7.5, 7.3, 7.6, and finally 8 am- 
 peres ) 
 
 After the operation the calcium carbide was covered 
 with grains of carbon. No explosion was noticed. A 
 deposit of crystalline zinc took place on the cathode 
 of platinum. 
 
 When calcium carbide was used as a cathode in an 
 electrolyte of zinc chloride, no ethylene was obtained. 
 In the third experiment performed with a calcium 
 carbide cathode, and a zinc anode, the carbide became 
 covered with large crystals of zinc The solution of 
 zinc chloride was acidified before the electrolysis, but 
 most of the acid was driven off by the heat of the 
 operation. 
 
 In the first experiment no gas was collected. The 
 object of the operation was to find whether chlorine 
 
-6 4 - 
 
 exploded with nascent acetylene at the anode. It was 
 found that the chlorine united with the calcium of 
 the carbide, while the carbon was separated in a hard 
 gritty mass. L,ittle or no free chlorine was noticed. 
 The temperature of this operation ranged from 
 124 C. to 132 C. No reason has been found for the 
 great variations of current that were observed. 
 
 RESULTS OF THE EXPERIMENTS. 
 
 TIME. 
 
 TEMP. 
 
 VOLTS 
 
 AMP. 
 
 GAS 
 
 OBT'D. 
 
 C 2 H 2 . 
 
 45-2 
 7-3 
 
 C 2 H 4 . 
 
 H 2 . 
 
 [I.-3^ min. 
 
 io6C 
 iooC. 
 
 20. 
 
 10. 
 
 5-5 
 5 
 
 53 ccm 
 53.8 ccm 
 
 o. 
 
 0.2 
 
 23-3 
 
 ELECTROLYSIS OF CALCIUM NITRATE SOLUTION WITH CAL- 
 CIUM CARBIDE ELECTRODES. 
 
 Calcium nitrate like calcium chloride is well adapted 
 for electrolytic work with calcium carbide electrodes. 
 In acidified solution the product of reaction of the 
 acid electrolyte upon the electrode is calcium nitrate, 
 and thus mixtures of electrolytes are avoided. Cal 
 cium nitrate is as deliquescent as the chloride, and 
 solutions of any concentration may be obtained. 
 
 In the first experiment the electrolysis was per- 
 formed at ordinary temperatures and under atmos- 
 pheric pressure, in the other operations additional 
 pressure was applied. The apparatus in the first 
 operation was of the type as shown in figure ( 3 ) , and 
 a cathode of calcium carbide was used. As a con- 
 centrated solution of calcium nitrate does not attack 
 the carbide electrode very readily even in the presence 
 of nitric acid, water was added until a good evolution 
 
-6 5 - 
 
 of acetylene was obtained. The temperature in the 
 first experiment rose from 18 C. to 30 C. 
 
 RESULTS OF THE EXPERIMENT. 
 
 TEMP. 
 
 VOLTS 
 
 AMPERES. 
 
 GAS 
 
 OBT'D. 
 
 C 2 H 2 . 
 
 ABSORPTION 
 BY H 2 S 2 O 7 . 
 
 1 8 -30 C. 
 
 10. 
 
 2.7-35. 
 
 53.4 ccm 
 
 14.4 
 
 0.8 ccm. 
 
 ELECTROLYSIS OF CALCIUM NITRATE UNDER PRESSURE. 
 
 An attempt was next made to electrolyze calcium 
 nitrate solution with calcium carbide electrodes under 
 pressure. In view of the difficulties of obtaining 
 proper connections with the carbide electrode, it was 
 not easy to find a completely desirable method with 
 apparatus that could easily be set from the ordinary 
 laboratory supplies. The apparatus used is shown in 
 figure ( 6 ). 
 
 The vessel in which the electrolysis was performed 
 was a thick-walled flask having two ground glass 
 openings, and a capacity of 500 cubic centimeters. Into 
 the larger of these openings a calcium carbide elec- 
 trode ( A ) was fitted. The smaller opening ( B ) was 
 closed with a two-holed rubber stopper that was 
 fastened to the apparatus with shellac. Through one 
 of the holes of this stopper passed the tube (C), to 
 conduct the gas into the Hempel burette (D), the 
 amount of gas being regulated by the stop-cock ( K). 
 Through the other hole passed the long glass tube 
 ( F ) which went to the bottom of the vessel and dip- 
 ped below the surface of a layer of zinc amalgam, 
 (G). This tube was nearly two meters long and 
 was graduated in centimeters throughout. Within 
 
66 
 
-6 7 - 
 
 this passed a small copper wire making connection 
 with the zinc amalgam that served as an anode. The 
 tube served also as a pressure gauge, the amount of 
 pressure being approximately indicated by the height 
 of the mercury in the tube, as the gas increased 
 within the apparatus. The amount of pressure was 
 read off on the tube in centimeters. The function of 
 the amalgam was to reduce the oxygen ions given off 
 at its surface with the formation of water. The acid 
 present in the electrolyte acted on the amalgam giv- 
 ing off hydrogen which united with the oxygen set 
 free to form water. 
 
 The gas was allowed to escape only at definite 
 stages and only as fast as it was formed within the 
 apparatus. This was done by regulating the outflow 
 at ( G ) through the capillary tube and into the 
 Hempel burette. Pure mercury was poured into the 
 long tube to displace the amalgam therein and thus 
 give a correct reading of the pressure. 
 
 The calcium carbide cathode is shown more in 
 detail in figure ( 7 ) in order to illustrate the connec- 
 tion of the various parts with more exactness. 
 The calcium carbide ( A ) was made into a pencil of 
 as evenly cylindrical a shape as possible. This was 
 fitted into a small screw-cap specimen-bottle after its 
 bottom has been removed. A piece of soft rubber 
 tubing ( B ) passed closely and tighty with the car- 
 bide into the bottle and was reversed outside of the 
 same. The rubber was well tied to both carbide and 
 bottle, so that any pressure within the apparatus 
 rendered the connections closer, and less liable to 
 leak, and at the same time held the electrode in posi- 
 
68 
 
 tion. Around the bottle was fitted a good cork ( D ) 
 which was fixed to the opening with asphalt, and 
 allowed to dry several days in an atmosphere free 
 from moisture. The space ( C ) in the small bottle, 
 not occupied by the electrode was filled with mercury 
 to secure good electrical contact. When good con- 
 tact was not obtained the heat became so great at the 
 surface of the calcium carbide as to ignite the rubber, 
 owing to the resistance of the cathode to the passage 
 of current. A rubber washer ( K ) with a hole in its 
 center was inserted above the mercury. The plate 
 ( F ) of chemically pure iron was put in to prevent 
 the mercury from attacking the metal cap, which was 
 screwed on tightly over the glass bottle. 
 
 The circuit was closed after connecting ( H ) in 
 ( Figure 6 ) with the battery by contact of the wire 
 ( I ) with the screw-cap of the bottle. The current 
 passed through the iron plate and mercury to the 
 electrode ( A ) , where the gaseous products were 
 evolved. 
 
 When the apparatus was ready and the stoppers 
 were well dried, the mercury amalgam was poured 
 into the vessel by a long thistle-tube drawn out at 
 the end. The acidified nitrate solution was poured 
 in through the short glass tube, ( C ) by inserting 
 within ( C ) a thistle-tube drawn out to a fine point. 
 The vessel was filled about five-sixths full of the 
 liquid. The apparatus was connected with a Hempel 
 burette and electrolysis begun by making contact at 
 (H) and (I). Two experiments were made and 
 results obtained at three different stages of pressure 
 for each operation. 
 
-6 9 - 
 
 In the first experiment, the operation was carried 
 on with a current of one-half an ampere and ninety- 
 nine volts electromotive force. When the contact 
 was made the gas was allowed to pass out for some 
 time. Then the stop-cock at ( K ) was closed, and 
 the mercury rose slowly in the tube ( F ) , as the 
 pressure within increased. When a pressure of 
 1530 mm. of mercury was obtained, the gas at ( K) 
 was allowed to pass into the Hempel burette only so 
 fast, however, as to keep the reading continually at 
 1530 mm. while the burette was being filled. The 
 stop-cock at (K) was closed and another Hempel 
 burette substituted to obtain products at higher pres- 
 sure. The experiment was continued with the inten- 
 tion of obtaining the gas at a pressure of 1900 mm. 
 When the column of mercury reached 1860 mm. of 
 mercury in height, the calcium carbide electrode was 
 violently blown out with a loud report. 
 
 Another attempt was made after the apparatus had 
 been set up again. The gas was collected at different 
 stages of the experiment : 
 
 i. At ordinary atmospheric pressure. 
 
 2. At a pressure of 1 140 mm. of mercury. 
 
 3. At a pressure of 1460 mm. of mercury. 
 
 At a pressure of 1610 mm. the cathode was again 
 forced out and thus only three specimens of gas were 
 obtained. Owing to the fact that so little was left 
 after the elimination of acetylene the residues of the 
 three analyses were united and examined for ethy- 
 lene, hydrogen and ethane. The ethane was deter- 
 mined with the Winckler's pipette and as no diminu- 
 tion of volume occurred, it was then passed into the 
 
70 
 
 explosion pipette over mercury and exploded with a 
 spark from an induction coil. When the gas then 
 passed over caustic potash only 5.4 ccm. of gas were 
 absorbed. Accordingly only traces of saturated hydro- 
 carbons were present. 
 
 RESULTS OF THE EXPERIMENTS. 
 
 TEMP. 
 
 PR'SSURE 
 
 VOI/T. 
 
 AMP. 
 
 GAS COL- 
 LECTED. 
 
 ACETYL'NE 
 
 I. 16 C. 
 II. 16 C. 
 III. 16 C. 
 IV. 16 C. 
 
 1530 mm. 
 760 mm. 
 1140 mm. 
 1460 mm. 
 
 99- 
 
 IOO. 
 IOO. 
 IOO 
 
 0.5 
 I -3 
 i -3 
 i -3 
 
 58.7 
 82.6 
 
 79- 
 
 82. 
 
 32.4 
 
 7 8.61 
 76.3 \- toll 
 79- J 
 
 
 ETHYLENE. 
 
 HYDROGEN. 
 
 ETHANE- 
 
 RESIDUE OF 
 GAS. 
 
 I. 
 II. 
 
 o 
 2. ccm. 
 
 .5 ccm. 
 
 2.7 ccm. 
 
 4-5 ccm. 
 
 ELECTROLYSIS OF NITRATES AT A TEMPERATURE ABOVE 
 100 C. 
 
 ELECTROLYSIS OF CALCIUM NITRATE. 
 
 After electrolyzing calcium nitrate at ordinary tem- 
 peratures, with or without pressure, and not obtaining 
 any marked results as to yield of ethylene at a cathode 
 of calcium carbide, the next attempt was made to 
 electrolyze the same solution at a higher temperature. 
 This experiment was tried with as concentrated a 
 solution as yielded a good quantity of acetylene in 
 the heated electrolyte in the presence of nitric acid. 
 Nitric acid had been added before boiling but most of 
 it was driven off at the boiling point of the solution. 
 Before collecting the gaseous products the current 
 
was allowed to pass for some time in order to obtain 
 a uniform action and a steady flow of gas. 
 
 In the first experiment a cathode of calcium carbide 
 was used and a piece of platinum foil as an anode. 
 The apparatus was of the type shown figure ( 3 ) . 
 Brown fumes of the oxides of nitrogen were given 
 off. After the electrolysis these oxides were reab- 
 sorbed by the electrolyte and the operation had to be 
 repeated in order to obtain sufficient gas to submit to 
 analysis. Another constituent of the gaseous pro- 
 duct was absorbed in the water of the Hempel 
 burettes after standing for some hours. In the first 
 experiment the gas was passed over caustic potash in 
 order to remove the acid vapors of the oxides of 
 nitrogen. 
 
 The first and second experiments record the cathode 
 reactions, whereas the third gives the anode products. 
 
 RESULTS OP THE EXPERIMENTS. 
 
 TEMPERATURE. 
 
 voi/rs 
 
 AMP. 
 
 GAS COI,- 
 I,ECTED. 
 
 GAS SOIvUBIvE 
 IN WATER. 
 
 I. 106.5 C. 
 II. 107.5 C. 
 -104 5 C. 
 III. 110 C. 
 
 10. 
 
 10. 
 10 
 
 5-4 
 
 6-5-3 
 6-4.6 
 
 40.4 ccm. 
 
 58.5 ccm. 
 36 8 ccm. 
 
 I. 
 
 12-5 
 
 3- 
 
 T 
 
 II.' 
 III. 
 
 OXY- 
 GEN. 
 
 ABSORPTION 
 BY KOH. 
 
 C 2 H 2 . 
 
 ABSORPTION BY 
 
 H 2 SO 4 *SO 3 . 
 
 HYDRO- 
 GEN. 
 
 RESI- 
 DUE. 
 
 4 
 
 10. 
 
 8.6 
 
 20. 
 14-3 
 
 9- 
 15-7 
 10.5 
 
 24. 
 
 9- 
 
 ELECTROLYSIS OF ZINC NITRATE. 
 
 Calcium carbide was used as a cathode in the elec- 
 trolysis of a concentrated acidified solution of zinc 
 
nitrate. The apparatus represented in figure ( 3 ) 
 was used. In all the experiments performed with 
 this electrolyte great variations of current took place. 
 Brown fumes were evolved both at the anode and 
 at the cathode of calcium carbide when a solution 
 was electrolyzed. The operation had to be inter- 
 rupted several times to allow the acid fumes to be 
 reabsorbed by the solution. In this way sufficient 
 gas was collected to be submitted to analysis. 
 
 In the second and third experiment of this series 
 the anode actions were studied. The gas that was 
 collected was allowed to remain in the burettes sev- 
 eral days in order to take up acid vapors given off 
 during the electrolysis. 
 
 RESUI/TS OF THE EXPERIMENTS. 
 
 DURATION. 
 
 TEMPERATURE 
 
 voi/r. 
 
 AMP. 
 
 GAS COUvECTED. 
 
 I. 
 II 
 III. 
 
 2^M. 
 
 25Sec. 
 
 ii2.5-io6 C. 
 109 -100 C. 
 io9.5-n6.5 C. 
 
 10. 
 
 10. 
 
 10. 
 
 3-5-5- 
 
 7-5-8. 
 3-5-5 
 
 41. 
 51.8 
 29.8- 
 
 GAS SOLUBLE 
 IN WATER. 
 
 ACETYLENE. 
 
 GAS ABSORBED BY 
 
 H 2 S0 4 -H)SO R . 
 
 RESIDUE. 
 
 I.- 
 II. 
 III. 
 
 4-3 
 17.9 
 
 20.6 
 
 39-3 
 2.4 
 
 14.8 
 44 
 
 83 
 
 As in the experiments just described in the elec- 
 trolysis of nitrates at higher temperatures a consider- 
 able absorption took place when the gas freed from 
 acetylene was passed over fuming sulphuric acid, it 
 was necessary to ascertain whether it were ethylene. 
 Since, however, the same absorption occurred when 
 the anode products were thus treated it was evident 
 
73- 
 
 that the gas could not be ethylene. In order to show 
 that no ethylene was present as a product of the 
 cathode reactions when a heated solution of nitrates 
 was electrolyzed, the experiments were repeated and 
 after all the acetylene had been removed, the residual 
 gas was passed over bromine water in a Hempel 
 pipette and likewise into the Bunte-Seger burette 
 where the gas was shaken with bromine water. Abso- 
 lutely no absorption was obtained thus clearly show- 
 ing that the gas was not ethylene nor any other 
 unsaturated hydrocarbon. 
 
 The gas could not have been nitrogen trioxide or 
 peroxide as these are absorbed by water or at least 
 by caustic potash. In order to show that the gas 
 absorbed by the sulphuric acid in the pipette was 
 nitric oxide, the gas was collected in considerable 
 quantity. The solution of calcium nitrate was elec- 
 trolyzed in a flask fitted with a three-holed stopper. 
 The platinum anode was contained in a Gooch tube 
 dipping below the electrolyte so that no gas from the 
 anode could escape into the flask but was carried away 
 as fast as it was formed. A pencil of calcium carbide 
 served as a cathode, and the gas evolved was carried 
 through a tube bent at right angles into a gasometer. 
 The gas was allowed to remain in the gasometer for 
 several weeks to remove all the other oxides of nitro- 
 gen. When air was then drawn into the flask the 
 presence of nitric oxide was manifested by the forma- 
 tion of brown fumes of peroxide. The absorption 
 over fuming sulphuric acid was then concluded to be 
 due to nitric oxide according to the reaction : 
 
74 
 
 ONO 
 
 
 3 S0 3 -f 2NO = 
 
 O +S0 2 . 
 - 
 
 ONO 
 
 ELECTROLYSIS OF MERCURIC NITRATE. 
 
 In electrolyzing a solution of the salt a cathode of 
 calcium carbide was used in an apparatus as shown 
 in figure (3). As mercuric nitrate is very little 
 soluble in water, a solution was heated with an excess 
 of the solid remaining in the vessel during electrolysis 
 so that the quantity of the solution might remain 
 constant. An anode of platinum was used and nitric 
 acid was added to the solution. Most of the acetylene 
 given off from the electrode united with the mercuric 
 nitrate to form compounds described by Hoffman. 1 
 The mercuric nitrate did not dissolve fast enough to 
 permit a slow action at the cathode. 
 
 RESULTS OF THE EXPERIMENT. 
 
 TEMPERATURE- 
 
 VOLT. 
 
 AMP. 
 
 GAS COLLECTED 
 
 ^2^2- 
 
 C 2 H 4 . 
 
 8 7 -97C. 
 
 50. 
 
 .9-1.2. 
 
 J9.2 
 
 8.2 
 
 .6 
 
 An attempt was made to repeat this experiment, 
 but the solution had become so dilute and the action 
 on the electrode so rapid that of47.4ccm. of gas, 32.2 
 ccm. were found to be acetylene. 
 
 In the examination of ammonium nitrate in a 
 heated solution, with a cathode of calcium carbide, a 
 large proportion of acetylene was obtained, ammonia 
 
 1 Ber. 31, 2213. 
 
-75- 
 
 gas was evolved, but practically 110 other gaseous 
 products resulted. Sodium hyposulphite, stannic 
 chloride and various other salts were also electrolyzed 
 with calcium carbide electrodes, but no results were 
 obtained that differed from those already recorded. 
 In the electrolysis of cupric ammonium chloride no 
 gaseous products could be collected owing to the 
 voluminous precipitates that clogged up the burette. 
 The precipitate was first of a light green color, a 
 brown powdery precipitate was then formed and 
 finally it became black. These compounds were, how- 
 ever, formed independently of the action of current, 
 as was subsequently found on heating the double 
 chloride with calcium carbide. 
 
 From the results of the investigation just described 
 it is evident that if acetylene unites with nascent 
 hydrogen at the cathode only the faintest traces of 
 ethylene were found. In no experiment performed 
 were more than traces of ethyleue at a cathode of cal- 
 cium carbide obtained. The formation of alcohol at 
 the cathode, mentioned by Bilitzer, does not seem to 
 me to have been sufficiently substantiated. 1 It has 
 been shown that acetylene in the presence of sulphuric 
 acid gave acetaldehyde. This gave the iodoform 
 test as readily as alcohol. Since with unplatinized 
 electrodes no ethyleue is obtained at the cathode, it 
 may be concluded that the synthesis of the gas 
 results from catalytic action of the reduced platinum 
 in effecting the union of acetylene and hydrogen. 
 This synthesis was in fact effected by Wilde 1 as 
 
 1 Ber. 7,353. (Bull, d' Acad. Royal, de Belg. 2, XXI., No. I, 
 1874.) 
 
- 7 6- 
 
 already referred to in the introduction to this work. 
 Sufficient ethylene was not formed in Bilitzer's ex- 
 periment to account for the amount of iodoform pre- 
 cipitate actually obtained from the products of 
 electrolysis of sulphuric acid. As practically no ethy- 
 lene was obtained the resulting iodoform is to be 
 referred to the formation of acetaldehyde. 
 
 In fact, by passing acetylene for some time into 
 reduced platinum suspended in water acidified with 
 dilute nitric acid, aldehyde was formed. When the 
 filtered solution was treated with iodine and caustic 
 potash, an abundant precipitate of iodoform was 
 obtained. 
 
77 
 
 THE CHLORINATION OF ACETYLENE. 
 
 HISTORY OF THE REACTION OF CHLORINE WITH 
 ACETYLENE. 
 
 The action of acetylene upon chlorine was first ob- 
 served in 1835 by Edmond Davy, 1 who, in a paper 
 read before the Royal Dublin Society, reported the 
 instantaneous explosion that occurred when the two 
 gases were brought together. No further investiga- 
 tion of this subject seems to have been made until 
 1860 when Berthelot 2 who had given the hydrocarbon 
 its name, acetylene, declared that the gas mixed with 
 chlorine gave rise to violent explosions in diffused 
 daylight. He thus seems to infer that the sudden 
 decomposition noticed by Davy is primarily due to 
 the influence of actinic light rays. Wohler 3 two years 
 later refers to the explosiveness of mixtures of 
 chlorine and acetylene, but assigns no cause for the 
 phenomenon. 
 
 The same year Berthelot stated the failure to make 
 di-chloride of acetylene, (C 2 H 2 Cl 2 ),by direct union 
 of the constituents, owing to the violent explosions 
 that resulted. 
 
 In 1866, however, Berthelot 4 came to the conclusion 
 
 1 Ann. 23, 144. 
 
 2 C. R., sr, 1044. Ives Carbures D'Hydrogene Paris, 1901. 
 'Ann. 124, 220. 
 
 4 Les Carbures D'Hydrogene t. I, p. 309. 
 
- 7 8- 
 
 that a mixture of acetylene and chlorine could be 
 preserved in the dark for several days, but that an 
 explosion took place as soon as brought to the light. 
 He found, moreover, that under certain conditions, 
 the exact nature of which he confessed himself unable 
 to determine, the di-chloride of acetylene was formed. 
 
 The union would continue quietly for some time, 
 yet finally, and almost invariably a violent detona- 
 tion, or spontaneous noiseless combustion with the 
 evolution of light and deposition of much carbon re- 
 sulted. These effects were noticed as well when an 
 excess of chlorine or an excess of acetylene was used, 
 or even when either gas was diluted several times its 
 volume of hydrogen or carbon dioxide. He now 
 refers the cause of the phenomenon to the formation 
 and spontaneous decomposition of the substituted 
 chloride of acetylene, (C 2 HC1), which breaks down 
 spontaneously and violently in contact with oxygen 
 of the air. He confesses, however, his inability to 
 assign a definite cause supported by the evidence of 
 experiment. He believes the explosion results be- 
 cause of a ' ' certain molecular inertia ' ' at the moment 
 the gases are mixed, or on calorific phenomena at the 
 point where the reaction begins. 
 
 In 1880 some light .seemed to be thrown upon the 
 subject by Wallach. 1 He found that when heating 
 dichlor- acrylic acid, or its salts with alkalies or the 
 hydrates of the alkaline earth metals, a gas was given 
 off which took fire spontaneously, or exploded in con- 
 tact with the air. By diluting the evolved gas with 
 
 1 Ann. 203, 83. 
 
79 - 
 
 hydrogen aud passing it into bromine, he obtained 
 and analyzed the compound, C 2 HC1 Br 4 thus show- 
 ing the composition of the gas to be a substituted 
 chlor-acetylene of the formula C 2 HC1. As already 
 stated, Berthelot referred to this substance as the 
 cause of the explosion when acetylene and chlorine 
 are directly united. 
 
 In 1884 Schlegel 1 came to the conclusion that the 
 sole cause for the phenomenon of spontaneous decom- 
 position of a mixture of the two gases is the action of 
 light rays. He showed that the mixture could be 
 kept for an indefinite time in the dark, but that the 
 light of a gas flame is sufficient to explode the gases. 
 
 Romer 2 two years later assigns another cause for 
 the phenomenon of detonation. He allowed the 
 acetylene he used to stand some time in diffuse day- 
 light, and found that the walls of the glass vessel 
 containing the gas became coated with a brown pro- 
 duct. This he supposed to be a polymerized poly- 
 acetylene resulting from the di-acetylene ( C 4 H 2 ) , 
 discovered shortly after by Bayer. 3 Romer referred 
 the explosion of acetylene and chlorine to the im- 
 purity just mentioned because of its instability. 
 Acetylene purified by exposure to light before being 
 brought into contact with chlorine, united quietly to 
 form addition products, whereas freshly prepared 
 acetylene always gave rise to a sudden explosion. 
 Romer concludes that acetylene like ethane, ethy- 
 
 1 Ann. 226, 153. 
 
 2 Ann. 233, 215 and 184, (3) Ann. Chim. Phys. 16,473. 
 Carb. d'Hyd. vol. I. 
 
 3 Ber. 18, 2272. 
 
8o 
 
 lene, and carbon monoxide are analogous in their 
 action towards chlorine, and like hydrogen, will 
 explode with chlorine only under the influence of the 
 action of rays of light. 
 
 In 1872 Berthelot and Jungfleisch effected the 
 chlorination of acetylene by means of antimony 
 pentachloride. This compound absorbs the gas with 
 the formation of a substance corresponding to the 
 formula C 2 H 2 SbCl 5 , which separates in well denned 
 crystals. With water, decomposition takes place and 
 on heating, a mixture of di-and tetra-chlorides of 
 acetylene distills over. When the crystalline com- 
 pound is heated with an excess of antimony penta- 
 chloride, pure tetrachlorethane is obtained. In the 
 distillation explosions very frequently occurred. 
 There is also much danger in passing acetylene into 
 heated antimony pentachloride. The reactions of this 
 method of preparing the chlorides of acetylene were 
 represented by the authors by the following equations : 
 
 C 2 H 2 + SbCl 5 =C 2 H 2 'SbCl 5 . 
 
 C 2 H 2 SbCl 5 =C 2 H 2 Cl 2 + SbCl 3 . 
 
 C 2 H 2 'SbCl 5 + SbCl 5 =C 2 H 2 Cl 4 + 2SbCl 3 
 
 Sabanejeff in 1883 repeated these experiments of 
 Berthelot and Jungfleisch 1 in order to obtain the di- 
 chloride of acetylene, and the intermediate compound 
 C 2 H 2 'SbCl 5 , but with little success. The absorption of 
 the gas took place with great difficulty, and with 
 very little evolution of heat. Shaking the contents 
 
 1 Ann. 216, 257. 
 
8i 
 
 of the flask often gave rise to an explosion. Sabane- 
 jeff could not obtain the crystalline compound of 
 acetylene with antimony pentachloride, though he 
 claimed to have continued the process a long time. 
 
 Still another cause assigned for the phenomenon of 
 explosion of an acetylene and chlorine mixture is pro- 
 posed by Nef. 1 He supposes that the decomposition 
 is due to the presence in acetylene of an impurity, as 
 Romer thought. The polyacetylene of the latter 
 author is declared by Nef to be nothing else than an 
 isomeric form of acetylene represented by the formula 
 C:CH 2 , which he calls acetylidene. The substituted 
 acetylene chloride discovered by Wallach, is accord- 
 ing to Nef, to be represented by the formula C1HC : C 
 a derivation of acetylidene, both of these compounds 
 being very unstable and liable to spontaneous and 
 violent decomposion. 
 
 In 1898 Mouneyrat 2 threw some light upon the 
 reaction of chlorine and acetylene, and made a 
 thorough study of the nature of the explosion that 
 occurs when the gases are mixed. He obtained 
 acetylene by the action of aluminium chloride upon 
 ethylene chloride. By passing chlorine in the mixture, 
 the acetylene given off reacted forming principally 
 the symmetrical and unsym metrical tetrachlor- 
 ethanes. No explosions were obtained in this reaction. 
 
 The author proceeds then to show that the phe- 
 nomenon of explosion in the union of acetylene and 
 chlorine is due to the presence of oxygen. When the 
 
 1 Ann. 298, 230. 
 
 2 Bull. Soc. Chim. (36, Ser.) XIX., 445. 
 
82 
 
 two gases, acetjdene and chlorine, were allowed to 
 pass simultaneously into a mixture of ethylene di- 
 chloride and aluminium chloride, no explosion occur- 
 red when proper care was used to exclude air during 
 the operation. The spontaneous quiet combustion 
 of the two gases could not, however, be prevented at 
 the beginning of the action, nor when both gases were 
 passed in too rapidly. An increased yield of acetylene 
 tetrachloride was obtained in this way and this was 
 due to the direct union of the two gases. 
 
 The two gases were also united in test tubes over 
 distilled water saturated with salt to drive out oxygen. 
 Union again took place quietly. If oxygen was in- 
 tentionally put into a test-tube before bringing the 
 "acetylene and chlorine together, a violent explosion 
 always occurred. This was supposed to be due to the 
 formation and spontaneous decomposition of the 
 unstable substituted chloracetylene, C 2 HC1, discov- 
 ered by Wallach. Mouneyrat concludes that mixtures 
 of chlorine and acetylene always combine quietly 
 with formation of tetrachloracetylene in diffuse day- 
 light, provided that there be no trace of free oxygen 
 or of compounds susceptible of giving off oxygen. 
 
 The author also suggests a method for the prepara- 
 tion of tetrachloracetylene in the laboratory by 
 passing acetylene and chlorine into a mixture of 
 ethylene dichloride and aluminium chloride. An 
 eighty per cent, yield is obtained. At higher tem- 
 peratures tetrachlorethane in the presence of alumi- 
 nium chloride is changed to hexachlorethane. 
 
 Mixed haloid acetylene compounds containing 
 chlorine have been obtained in various ways analo- 
 
8 3 - 
 
 gous to the formation of ethylene derivities of the 
 halogens. Accordingly by treating a solution of 
 iodine trichloride in hydrochloric acid with acetylene. 
 Plimpton 1 obtained monochloriodacetylene. Other 
 chloriodides appear to have been formed which are 
 richer in chlorine or iodine but on raising the tem- 
 perature of distillation, decomposition sets in with 
 the separation of iodine vapor. The bromochloride 
 of acetylene is prepared from the preceding com- 
 pound. It cannot be prepared pure from the chloride 
 of bromine. C 2 H 2 IBr is formed when acetylene is 
 passed into bromine moniodide in water. Other 
 mixed haloids of more complex formulas may have 
 been present in these operations, but could not be 
 separated undecomposed. 
 
 In 1883 Sabanejeff 2 published an investigation on 
 the mixed haloid derivatives of acetylene. He suc- 
 ceeded in separating C 2 H 2 ClBr and C 2 H 2 Cl 2 Br 2 by 
 acting upon C 2 H 2 Br 2 with antimony pentachloride. 
 Sabanejeff treated iodine suspended in water with 
 chlorine and then passed acetylene into the solution. 
 
 Results like those of Plimpton were obtained. The 
 compounds C 4 H 2 C1 2 I 2 and C 2 H 2 C1 3 I were thought to be 
 present but could not be separated without decom- 
 position. When C 2 H 2 C1I was treated with alcoholic 
 potash a gas was given off which the author con- 
 cluded to be the explosive C 2 HC1. 
 
 !J. Ch. Soc. XLI., 392. 
 2 Ann. 216, 257. 
 
-8 4 - 
 
 DIRECT ACTION OF CHLORINE GAS ON ACETYLENE 
 
 GAS. 
 
 Although Mouneyrat has quite conclusively shown 
 that the cause of explosion between acetylene and 
 chlorine when brought together is referred to the 
 presence of oxygen, nevertheless very conflicting 
 results have been obtained which either leave the 
 problem more unintelligible, or point to [other 
 accompany causes. Results have been found that 
 point to the fact that simply the presence of oxygen in 
 diffuse daylight is not sufficient explanation for the 
 explosions that occur. Anyone who has studied the 
 results obtained by various investigators, or has tried 
 to attack the problem systematically cannot but be 
 struck by the apparent haphazard with which the 
 explosions take place. In the course of a single 
 experiment it often happens, that now quiet union 
 takes place with the formation of addition products 
 and again, by no apparent change of conditions, the 
 uniting gases form substitution products with violent 
 explosions. If oxygen be the sole cause of explosion, 
 no explanation has yet been offered as to the nature 
 of the action of this element in bringing about the 
 phenomenon. It has been suggested that the substi- 
 tuted acetylene, C 2 HC1, is the cause of the violent 
 decomposition of a mixture of acetylene and chlorine. 
 Both Berthelot and Mouneyrat have intimated this, 
 but no attempt has been made to suggest why this 
 compound should be formed because oxygen is 
 present, and why only acetylene tetrachloride is 
 formed under other conditions. The theory holding 
 that the substance, C 2 HC1 causes explosion when 
 
8 5 
 
 acetylene and chlorine are united, is based on no 
 other fact than that the compound, C 2 HC1 itself ex- 
 plodes, and that Wallach prepared this from di- 
 chloracrylic acid. No one has, however, shown that 
 acetylene and chlorine mixture gives rise to the 
 chloracetylene refered to, and there is no experimental 
 evidence that validates the supposition. 
 
 If the presence of oxygen is sufficient in itself and 
 necessary to cause explosion in a mixture of acety- 
 lene and chlorine, then the presence of oxygen ought 
 in every case give rise to violent detonation I have 
 performed a number of experiments that tend to dis- 
 prove this assumption. I had undertaken to see 
 whether the temperature of an experiment has any 
 connection with the explosion, but with what result 
 will be seen in the course of this work. 
 
 I. ACETYLENE AND CHLORINE HYDRATE. 
 
 Chlorine was passed into water surrounded by a 
 freezing mixture. Frequent shaking was resorted to 
 in order to obtain small crystals of chlorine hydrate. 
 When sufficient hydrate was obtained the product 
 was transferred to a beaker, to insure that no gas 
 collect above the liquid and so render doubtful 
 whether any action that took place be the result of 
 the union of the two gases, or of direct combination 
 with the hydrate. Neither a slow or rapid stream of 
 acetylene caused action with hydrate itself, neither 
 in subdued, diffuse, or direct sunlight. No action 
 was observed between the acetylene and chlorine 
 gases which escaped. All the chlorine was driven 
 out of solution by the acetylene, which was passed 
 
86 
 
 into the hydrate until a temperature of 2 1 C. was 
 obtained. No trace of tetrachloracetylene was ob- 
 tained. When bromine was added to the hydrate, 
 the red color disappeared by action of acetylene, but 
 the chlorine remained or was eventually drawn out 
 of solution without any apparent action. 
 
 Nascent acetylene did not give different results. 
 Calcium carbide granulated and powdered, showed 
 no chemical action or explosion. When, however, 
 the operation was performed in closed vessels so that 
 both gases mix above the solution, explosion took 
 place accompanied with separation of carbon. The 
 odor of hexachlorethane clung tenaciously to the 
 particles of soot. 
 
 2. ACTION OF A SOLUTION OF ACETYLENE IN ACETONE TO- 
 WARDS A SOLUTION OF CHLORINE IN CARBON TETRA- 
 CHLORIDE AT LOW TEMPERATURES. 
 
 Another attempt to unite acetylene and chlorine at 
 lower temperature was made in a different way. 
 Acetone at O C. dissolves about twenty-five volumes 
 of acetylene. Carbon tetrachloride dissolves twenty- 
 five per cent, of chlorine at the same temperature. 
 Various methods were used to unite the gases in these 
 solutions. Chlorine was passed into a saturated 
 acetone solution of acetylene, and similarly acetylene 
 gas into the chlorine solution of carbon tetrachloride. 
 Spontaneous combustion could not be avoided, espe- 
 cially in closed vessels. Explosions in test-tubes even 
 were very great. No direct action took place within 
 the solution in either case, all the explosions resulted 
 from gas mixtures above the liquid in the vessels. 
 
-8 7 - 
 
 As the solutions of gases could not be poured into 
 one another directly without spontaneous combustion, 
 one solution was introduced into the other slowly by 
 a dropping funnel dipping below the liquid. The 
 heat of reaction drove out the gases from solution 
 which then burnt with separation of clouds of carbon. 
 In examining the products no tetrachloracetylene 
 was found. The substances formed were chloracet- 
 ones. The carbon separated was mixed with hexa- 
 chlorethane in small quantity. 
 
 DIRECT UNION OF ACETYLENE AND CHLORINE AT I,OW 
 TEMPERATURES. 
 
 To test the effect of low temperatures on the action 
 of acetylene and chlorine the gases were, in another 
 type of experiment, passed simultaneously into a long 
 wide tube several inches in diameter. The operation 
 was performed in diffuse daylight on the window-sill 
 outside, at a temperature of .1 to .2 C. The large 
 glass tube was closed below by a* two-holed rubber 
 stopper. The chlorine was passed in by a smaller 
 glass tube, and acetylene through another tube bent 
 so as to dip below a layer of water. During one of 
 the experiments the top of the apparatus was left 
 open so that access of air was not excluded. In 
 another experiment the top of the larger glass tube 
 was connected with a large Gooch tube which dipped 
 below water in a beaker. Chlorine gas was first 
 passed into the apparatus and later acetylene. As 
 soon as the latter gas was led in, dense clouds of 
 white fumes appeared, indicating the formation of 
 tetrachloracetylene which in a few minutes began to 
 
88 
 
 condense and trickle down the sides of the tube No 
 explosion took place, no separation of carbon or 
 spontaneous combustion. The gases that escaped did 
 not burn, though both gases were passed in so rapidly 
 that the bubbles in the wash-bottles could not be 
 counted. After the gases had thus been allowed to 
 combine for more than an hour without any sign of 
 explosion or combustion, more than 30 grams of 
 tetrachloracetylene were formed. At the end of one 
 hour, several cubic centimeters of air were introduced 
 with the chlorine into the apparatus. No sign of 
 explosion or combustion was noted, and after another 
 hour had elapsed another expedient was tried to 
 ascertain the effect on the general action. Hitherto 
 the flow of gases, though both very rapid, had been 
 nearly equal with perhaps a slight excess in volume 
 of the chlorine. By quickly and vigorously shaking 
 the acid mixture of bleaching powder the flow of 
 chlorine gas was suddenly very much increased. 
 After a few seconds a faint brown cloud as large as a 
 candle flame began to form at the top of the large 
 tube. This puff of carbon slowly traveled down the 
 tube increasing in size, accelerating in velocity, and 
 becoming darker in color until near the chlorine tube 
 it became a quiet flame. Much carbon was deposited 
 at the lower end of the apparatus. The silent explo- 
 sion lasted about ten seconds. When the excess of 
 chlorine had been used up, the quiet union of acety- 
 lene and chlorine again proceeded with formation of 
 tetrachlorethane. 
 
 Another characteristic peculiar to the phenomenon 
 of explosion is, that whenever it occurs it is accom- 
 
8 9 - 
 
 panied with the formation of hexachlorethane. The 
 carbon separated by explosion seems to perform some 
 catalytic function in substituting the hydrogen atoms 
 of acetylene with chlorine. During two hours not a 
 trace of hexachlorethane was obtained though over 
 30 grams of acetylene tetrachloride resulted. During 
 explosion hexachlorethane is principally formed. If 
 the experiment be so regulated that the acetylene is 
 made to burn in an atmosphere of chlorine which is 
 easily done by bringing about a disturbance of the 
 equilibrium in the union of the two gases, such as I 
 have just referred to, the hexachlorethane is formed 
 in sufficient quantity to be sublimed in clear crystals 
 from the carbon mass. It may be likewise separated 
 from the excess of tetrachlorethane by driving the 
 latter over in dry steam. The tarry mass left behind 
 is a mixture of carbon and hexachlorethane the 
 latter can be separated with ether or by sublimation. 
 
 Berthelot in attempting to give an explanation to 
 the explosive nature of acetylene and chlorine 
 mixtures, supposed that the phenomenon was due to 
 the energy of union, so much heat being given off as 
 to cause partial decomposition of the products into 
 hydrochloric acid and carbon. 
 
 The formation of hexachlorethane at the moment 
 af spontaneous combustion seems to point to the fact 
 that the explosion of acetylene and chlorine mixtures 
 is due to the energy of reaction between the two gases 
 when brougth together. Acetylene being an en- 
 dothermic compound gives off great heat in decom- 
 position when substitution compounds are formed, 
 and substitution products are always formed during 
 
90 
 
 explosion of mixtures of the two gases. Even in 
 violent decomposition of very small quantities the 
 peculiar odor of hexachlorethane noticed after explo- 
 sion can be noted. No other substituted compounds 
 besides hexachlorethane were noticed. 4 
 
 It is also noteworthy that if the experiment is con- 
 ducted so as to obtain continuous combustion of 
 acetylene and chlorine, little or no tetrachloracetylene 
 is obtained, but the carbonaceous mass is rich in 
 hexachlorethane. This would lead us to believe that 
 the products of substitution are obtained according to 
 a reaction such as the following : 
 
 2 C 2 H 2 + 5 C1 2 = C 2 C1 6 + 4 HC1 + 2C. 
 
 The heat given off in breaking up a molecule of 
 acetylene and also as a result of forming hydrochloric 
 acid would be sufficient to propagate the explosion in 
 the residue of acetylene and chlorine according to the 
 reaction : 
 
 C 2 H 2 + C1 2 = 2HC1 + 2C. 
 
 I have noticed, morever, in the preparation of 
 tetrabromethane that if acetylene be allowed to enter 
 too rapidly into bromine cooled by ice water, the 
 same phenomenon of spontaneous combustion or total 
 decomposition with formation of substitution products 
 results owing to the energy of reaction. A very 
 rapid stream of acetylene will cause ignition of bromine 
 vapor. We should then expect that chlorine which 
 is more energetic than bromine in its action would 
 show the same phenomenon of explosion by the 
 violence of the reaction. In fact even ethylene under 
 certain circumstances will explode with chlorine 
 
though not as energetically as in the case of acety- 
 lene. Whatever may be the action of oxygen in 
 initiating, or helping the explosion of acetylene with 
 chlorine, it cannot be the sole cause of the phenome- 
 non, or its introduction in the experiment just de- 
 scribed would have caused explosion. As a matter 
 of fact not the least effect resulted. Not until after 
 an hour had elapsed did any explosion occur, and 
 then it was induced by other means. 
 
 CHLORINE AND ACETYLENE AT THE TEMPERATURE OF BOII,- 
 ING WATER. 
 
 Chlorine and acetylene were brought together into 
 a flask of boiling water connected with a condenser. 
 The latter in turn was connected with a closed receiver 
 and several small Wolff flasks containing water and 
 dilute caustic potash. After the water had been 
 boiling some time, chlorine was passed into the ap- 
 paratus until the air was displaced. Acetylene was 
 then passed into the flask and so regulated as not to 
 exceed one-half the volume of the chlorine entering. 
 An increased flow of acetylene results in an immediate 
 appearance of a flame in the condenser which burns 
 as long as the excess of gas lasts. If the proportion 
 of gases be well regulated no substituted acetylene is 
 formed. As soon as an excess of acetylene occurs, a 
 play of flames is noticed creeping slowly from the 
 lower part of the condenser to the point where the 
 steam condenses. If the whole apparatus be well 
 filled with chlorine previous to the entrance of acety- 
 lene no explosion takes place. The flames can more- 
 over, be prevented by regulating the stream of 
 
92 
 
 acetylene gas. It is important to have the flow of 
 acetylene so regulated that union takes place in the 
 flask when diluted with water vapor. The condensed 
 stream carries down with it drops of an oily liquid 
 which was collected, dried, and distilled. It was 
 found to be tetrachloride of acetylene, and had the 
 correct boiling point. A solution of dilute sulphuric 
 acid gave similar results when boiled. 
 
 It was noted that when acetylene were diluted in 
 the steam, no explosion in the flask occurred. Any 
 unused excess reaching the condenser was inflamed 
 therein. The play of flames can at will be stopped or 
 started by regulating the flow of acetylene. These 
 facts lead to the supposition that beside the presence 
 of oxygen and the influence of diffuse daylight as a 
 cause of explosion, the energy of reaction between 
 such active agents as acetylene and chlorine, is also 
 a factor not to be overlooked in considering the ex- 
 plosion of the gases. 
 
 ACETYLENE AND CHLORINE AT TEMPERATURES ABOVE IOO C. 
 
 In order to study the behaviour of acetylene to- 
 wards chlorine at temperatures above 100 C. the 
 gases were passed into a retort heated in an air-bath 
 to the desired temperature. The gases were dried 
 perfectly. In the first experiment the gases were 
 diluted with hydrochloric acid gas. The acetylene 
 and hydrochloric acid gas were passed through one 
 tube into the heated retort, and chlorine through 
 another tube. The air bath was heated to 230 C. 
 and chlorine was then passed in to displace the air in 
 the apparatus. The retort was as usual, connected 
 
93- 
 
 with a condenser, receiver, and wash-bottles to re- 
 move any products formed. Under these conditions 
 union of these gases took place quietly, neither 
 explosion or flames were noticed though the opera- 
 tion lasted all day. The interior of the retort was 
 found however, to contain considerable deposit of 
 carbon which was also swept down the jacket of the 
 condenser ; thus indicating that quiet combustion had 
 taken place in the dark. About 100 grams of tetra- 
 chloracetylene were obtained. It boiled at 147 C. 
 A considerable amount of hexachlorethane was also 
 found. It was removed by separating the tetrachlor- 
 ethane with steam and extracting the black residue 
 with ether. After evaporating the ether the crystals 
 were sublimed. The yield of oil was not so good as 
 when uniting the gases in the cold. I^ess oil was 
 obtained in proportion to the amount of acetylene 
 and chlorine used, and the duration of the process. 
 
 An experiment similar to the preceding, performed 
 at a temperature of 140 C. gave nearly the same re- 
 sults. The acetylene was not diluted with dry hydro- 
 chloric acid acid. The gases were passed into the 
 retort through separate tubes in the proportion of one 
 volume of acetylene to a little more than two volumes 
 of chlorine. The retort in the air-bath was connected 
 with a condenser with closed receiver, and several 
 Wolff flasks containing water and caustic potash. 
 Chlorine was passed into the apparatus first, and then 
 acetylene. After some time carbon was carried over 
 into the inner tube of the condenser which became 
 gradually coated. No explosion of flames were 
 noticed. The flow of chlorine was then suddenly in- 
 
-94 
 
 creased in volume, with the result that a play of 
 flame was seen within the condenser, beginning at 
 the bottom and passing slowly to the point of conden- 
 sation where it continued to burn brightly until the 
 excess of chlorine was used up. This sudden dis- 
 turbance of the equilibrium of the uniting gases 
 resulted, as in the other experiments, in the forma- 
 tion of substitution products. 
 
 As soon as the gases were again regulated carefully 
 the formation of tetrachlorethane continued quietly 
 throughout the greater part of the day until the 
 operation was finished. The products of reaction 
 were, as in the previous experiment, tetrachlorethane 
 and hexachlorethane. 
 
95 
 
 ACTION OF ACETYLENE TOWARDS CHLO- 
 RIDES AND CHLORINATING AGENTS. 
 
 REATION OF SULPHURYI, CHDORIDK WITH UNSATU- 
 RATED ALIPHATIC HYDROCARBONS. 
 
 Unlike the other oxy-chlorides, sulphuryl chloride 
 is principally a chlorinating agent. This action of 
 chlorination takes place in many instances by the 
 dissociation of the compound into its derivative com- 
 ponents, sulphur dioxide and chlorine, both being 
 present in the nascent state at the moment of reaction. 
 Many substances susceptible of union with the 
 halogens can accordingly take from sulphuryl chloride 
 its chlorine, which are not ordinarily or readily 
 capable of being effected in other ways. In some 
 instances the operation takes place by direct combina- 
 tion, in other cases the addition of aluminium chloride 
 is necessary as an intermediary for the reaction. 
 
 Sulphuryl chloride has been used mostly to effect 
 reactions in the aromatic series, 1 and here it manifests 
 its general property of substituting its halogen in the 
 place of one or more hydrogen atoms of those com- 
 
 1 Ber. 15, 1736. Bberhard, Inaug. Dissert, p. 13. (Zi866, 
 705.) Eberhard, Diss. p. n. Ber. n, 567, J. Pr. II., 17, 322. 
 Wenghofer, Inaug. Dissert. Rostock, 1894. Ber. 26, 2940. 
 Fram, Inaug. Dissert. Rostock, 1895. Gaz. XXX., i, 572. 
 Gaz. XXXII., II., 30. Gaz. XXVI., II., 403, (1896.) Gaz. 
 XXIV., I. p. 236, (1894.) Ber. 26, 2940. Gaz. XXVIII., I. 
 197. Gaz. XXVIII., I., 197, 1898. Gaz. XXIX., I., 340, 371, 
 383. Gaz. XXIX., I., 554. Gaz. XXXI., I., 464. Gaz. XXXI., 
 II., 184. 
 
9 6 
 
 pounds. With salts or their acids it behaves like the 
 chlorides of phosphorus, the hydroxyl being replaced 
 with the formation of acid chlorides. 
 
 The chlorination of inorganic substances has been 
 shown to be accelerated by the addition to sulphuryl 
 chloride of some aluminium chloride. This increase 
 of activity is ascribed to the power possessed by the 
 aluminium chloride of dissociating the sulphuryl 
 chloride into its component gases, both being present 
 in the nascent condition when a substance is added 
 that is capable of being united either to the chlorine 
 or to the sulphur dioxide. The action of the alumi- 
 nium chloride in this reaction is somewhat different 
 from its action in the ordinary cases in which it is 
 used as an agent for chlorinatian or condensation of 
 hydrocarbon residues. Ordinarily the action of alumi- 
 nium chloride seems to be that of forming a compound 
 with a hydrocarbon or an acid chloride. This double 
 compound breaks down an addition of water, and two 
 hydrocarbon or a hydrocarbon and a ketone residues 
 unite together. In case of chlorination, one of the 
 atoms in the chlorine molecule unites with the hy- 
 drocarbon residue while the other is joined to the 
 hydrogen atom abstracted from the hydrocarbon to 
 form hydrochloric acid which is evolved in the process 
 of decomposition with water. 
 
 Andrianowsky 2 in 1879 discovered that aluminium 
 chloride absorbs sulphur dioxide to form a compound 
 to which he ascribed the formula, A1C1' 2 SO 2 C1. This 
 is syrupy liquid that solidifies at 10 C. to a crystal- 
 line mass. On heating it attains the consistency of 
 anhydrous glycerine. On further heating it decom- 
 
97 
 
 poses giving off sulphur dioxide, and disulphur di- 
 chloride in small quantity, while aluminium chloride 
 and some aluminium sulphate are left. It is com- 
 pletely decomposed at 140 C. 
 
 Now Ruff 1 has shown that when sulphuryl chloride 
 dissolves aluminium chloride the compound, 
 A1C1 2 ' SO 2 C1, is formed, and on heating the solution, 
 can be obtained at the end of the operation. It is 
 supposed to be present even at ordinary temperatures 
 being formed according to the reversible reaction : 
 
 A1C1 3 + SO 2 C1 2 =^A1C1 3 'SO 2 + C1 2 . 
 
 He shows that the compound of aluminium chloride 
 and sulphur dioxide is formed. 
 
 It is then concluded that a real catalytic action in 
 the older sense of the word, occurs here ; for a single 
 addition of a small quantity of aluminium chloride is 
 sufficient to effect the chlorination of an indefinite 
 amount of sulphur, by starting an accelerated action 
 in the mixture at ordinary temperature. 
 
 In the action of aluminium chloride with sulphuryl 
 chloride, the end products are obtained by reason of 
 the formation of the substance A1C1 3 'SO 2 , or rather 
 because of the affinity between aluminium chloride, 
 A1C1 3 , and sulphur dioxide when any compound present 
 is capable of forming a stable chloride. The substance 
 A1C1 3 *SO 2 is, however, only a bye-product. The chlori- 
 nation is effected by reason of the tendency of aluminium 
 chloride to dissociate sulphuryl chloride, and unite 
 with the sulphur dioxide given off. This action of 
 
 l Ber. 35, 4453, (1903.) 
 2 Ber. 12, 688, 853. 
 
- 9 8- 
 
 influence of aluminium chloride in breaking up the 
 sulphuryl chloride molecule has been called by Ruff 
 "dissociation catalysis." The differences discussed 
 can be summed up by saying that in the general 
 aluminium chloride reactions, double compounds are 
 formed which are afterwards decomposed with water. 
 In the other instance, the aluminium chloride instead 
 of uniting with sulphuryl chloride breaks it up to 
 form the compound A1C1 3 'SO 2 , while nascent chlorine 
 is set free. This action will be well illustrated by the 
 experiments about to be described, namely ; the 
 chlorination of acetylene, ethylene, and amylene in 
 the presence of aluminium chloride, by means of sul- 
 phuryl chloride. 
 
 The chlorination of unsaturated hydrocarbons seems 
 to bring out the nature of the theory of RufF very 
 strikingly as addition products are formed. The 
 dissociated chlorine unites directly with the hydro- 
 carbon to form saturated compounds. The ordinary 
 chlorination reactions of hydrocarbons of saturated 
 series in the presence of aluminium chloride are 
 operations of substitution and hydrochloric acid is 
 evolved. With unsaturated compounds such as ethy- 
 lene, and acetylene, hydrochloric acid is not formed 
 but direct union takes place with one or or more 
 whole molecules of chlorine according to the number 
 of uncombined valencies of the hydrocarbon in 
 question. 
 
 By far the greatest amount of work with sulphuryl 
 chloride as a chlorinating agent has been done in the 
 aromatic series of the hydrocarbons. A number of 
 interesting reactions have of late been effected with 
 
99 
 
 inorganic compounds. Very few substances in the 
 aliphatic series have as yet been treated with sul- 
 phuryl chloride though the side chains of aromatic 
 compounds have been chlorinated in direct sunlight. 
 Allihn 1 tried the reaction of sulphuryl chloride on 
 acetone and acetoacetic ether, and he obtained mono- 
 and di-substitution products. Roubleff 2 succeeded in 
 chlorinating methylacetoacetic ether to a monosubsti- 
 tution derivative by using the proper proportions of re- 
 agent. Glacial acetic acid 3 gives small quantities of 
 acetyl chloride in the preparation of sulphuryl chloride 
 according to the method of Melsens. The principal 
 bye-product however, is monochloracetic acid. Boiling 
 glacial acetic acid gives more acetyl chloride when 
 treated with sulphuryl chloride. When succinimide 
 is heated in sealed tubes to 100 C. dichlormaleic acid 
 imide is formed which gives rise to dichlormaleic 
 acid when dilute alkalies are added. Behrend 4 ob- 
 tained from alcohol and sulphuryl chloride according 
 to the conditions of the experiment and the quantities 
 
 O TT O 
 
 of reagent used, the compounds 2 Qt>SO 2 , and 
 
 QH'O >S 2 ' Glyco1 gave thesubstance C * H *< QSK) 2 C1 
 The amines and their chlorides give respectively sul- 
 phones or sulphone chlorides of the corresponding 
 substituted ammonia. Piperidine 5 gives rise to sul- 
 
 1 Eberhard, Inaug. Dissert. Rostock. 1894. 
 
 2 Ann. 259. 254. 
 
 8 Eberhard, Inaug. Dissert. Rostock, 1894. 
 
 4 Ber. 17, 9. Ann. 222, 116, 136. 
 
 5 Fram. Inaug. Dissert. Rostock, 1895. 
 
too 
 
 phopiperidid. Mercaptan 1 with sulpliuryl chloride 
 yields as a final product, after separation of hydro- 
 chloric acid and sulphur dioxide, ethyl disulphide 
 
 C H *S 
 
 25 Sodium mercaptide was used instead of the 
 C 2 H 5 *S. 
 
 alcohol. 
 
 The sulphuryl chloride used in the following 
 experiments was obtained from several sources. Some 
 was made according to the method of Melsens, 2 an- 
 other product was made by the method of Schultz, 3 
 finally, sulphuryl chloride obtained from Kahlbaum 
 was used. In every case the same results were 
 obtained in the final reactions, yet in some instances 
 the yield of product was smaller owing to the presence 
 of impurities that reacted with aluminium chloride 
 directly, and thus retarted its catalytic action. 
 
 CHI.ORINATION OT? ACETYLENE WITH SULPHURYI. CHLORIDE 
 IN THE PRESENCE OF ALUMINIUM CHORIDE. 
 
 As none of the aliphatic hydrocarbons have as yet 
 been treated with sulphuryl chloride, no conclusion 
 can be drawn whether any difference of action might 
 be found between the behaviour of saturated and un- 
 saturated compounds of the series. The object of the 
 investigations about to be described, is the action of 
 sulphuryl chloride upon the lower members of the 
 unsaturated paraffines, ethylene, and also upon ethy- 
 lene and amylene. 
 
 1 Ber. 1 8, 3178. 
 
 2 C. R. 76, 92, also Eberhard, Inaug. Dissert, p. 8, 
 Rostock, 1894. 
 
 3 J. Pr. Ch. 23, 351. Ber. 14. 989, 2225. 
 
101 
 
 Perfectly dry acetylene does not react with sul- 
 phuryl chloride at ordinary temperature. The gas 
 was passed into the chloride for a whole day without 
 the faintest trace of reaction. Even when the con- 
 tents of the flask were raised to boiling temperature, 
 no better results were perceived. If, however, a small 
 amount of aluminium chloride be added to the sul- 
 phury 1 chloride, the action is soon made manifest by 
 the heat evolved, or the more or less complete absorp- 
 tion of the acetylene passed in. The contents of the 
 flask were decomposed by being poured slowly into 
 water at low temperature, and a liquid, having the 
 ethereal odor of chloroform was left behind. There 
 were likewise traces of evil-smelling sulphur com- 
 pounds. These latter reminded one forcibly of a 
 mixture of mercaptan and mustard oil. The residue 
 of organic oil, after standing under water for some 
 twelve hours and being washed with dilute caustic 
 potash solution and then with water, was dried over 
 calcium chloride and distilled. The contents of the 
 distilling flask went over at a temperature ranging 
 from 120 C. to 1 60 C. then decomposition set in 
 accompanied with the appearance of white fumes and 
 the separation of carbon in a hard gritty mass. Most 
 of the oil boiled between 1 40 to 1 45 C. (uncorrected. ) 
 Not the least trace of sulphur was found in the latter 
 fraction. Though the material used for distillation 
 was quite small, it was evident that the principal 
 product was tetrachloracetylene, whose boiling point 
 is 147 C. 
 
 In accordance with the conclusions arrived at by 
 Ruff, it is evident that the action of aluminium chlo- 
 
IO2 
 
 ride in the presence of sulphuryl chloride is to 
 accelerate the operation by bringing about chemical 
 dissociation. If, however, chlorine were present in 
 the free state, we should expect according to the 
 results arrived at in the preceding work, that when 
 acetylene were passed into the solution of sulphuryl 
 chloride, explosions w@uld occur. The acetylene, 
 however, was chlorinated to tetrachlorethane without 
 even the phenomenon of spontaneous combustion. 
 
 It was noted that in the previous experiment the 
 yield of chloride of acetylene seemed to bear some re- 
 lation to the amount of aluminium chloride used, 
 since only a small amount of the oil was obtained even 
 after passing acetylene gas into the mixture for many 
 hours. It was supposed that a double compound 
 with aluminium chloride is formed which is decom- 
 posed by water, one of the products being tetra- 
 chloracetylene. Accordingly, about 150 grams of 
 aluminium chloride were added to 250 grams of sul- 
 phuryl chloride, in order to insure complete and rapid 
 decomposition at ordinary temperature. The appara- 
 tus used, consisted of a round-bottom flask fitted with 
 a two-holed stopper, one hole for a reflux condenser, the 
 other for a glass tube through which the acetylene 
 was introduced. The acetylene was obtained from an 
 ordinary dip-generator, and was dried by passing 
 through concentrated sulphuric acid in a wash-bottle. 
 To insure complete separation of moisture it was next 
 passed through a drying cylinder containing pieces of 
 calcium carbide of the size of a pea. In this way very 
 rapid streams of acetylene can be effectually dried 
 and the traces of acid carried over from the wash- 
 
-103- 
 
 bottle of sulphuric acid are also removed by the 
 carbide. 
 
 In thus passing acetylene into the mixture of 
 sulphuryl chloride and aluminium chloride the con- 
 tents, according to the theory of Ruff, ought to be 
 strongly dissociated by the gas, especially when a 
 rapid stream is allowed to enter. No particular care 
 was used to exclude air. In fact air was purposely 
 introduced and no explosion was ever found to take 
 place. Even when heated on a water-bath while the 
 gas was being passed into the mixture, no sign of 
 explosion or combustion was observed. This fact is 
 noteworthy because as Ruff has shown, free chlorine 
 is evolved even at moderate heat. 
 
 It was found that it is not necessary to heat the 
 sulphuryl chloride and aluminium chloride to obtain 
 reaction. In fact, much heat is evolved and after 
 passing the gas into the mixture some minutes, the 
 contents of the flask became quite warm. Ordinarily, 
 with small amounts of substance no cooling need be 
 resorted to, but this may be made necessary as de- 
 composition products are formed when the heat is too 
 great. The mixture becomes dark purple or even 
 black. When the flask is moderately warmed by the 
 heat of reaction, the acetylene is absorbed as fast as it 
 can be brought into the apparatus. The contents 
 ought not to be allowed to take on a darker hue than 
 auburn or brown. After some time the heat of reac- 
 tion slackened and the absorption ceased. The 
 experiment had lasted five hours. The contents of 
 the flask were then poured into several liters of cold 
 water. With constant stirring the decomposition 
 
104 
 
 could be rather quietly effected. A clear amber- 
 colored oil separated at the bottom of the vessel, and 
 at the same time white fumes were given off during 
 the operation. A most penetrating and disagreeable 
 odor was perceived. The fumes also effected the eyes so 
 powerfully as to make it impossible to perform the 
 work except in a well ventilated hood. A painful 
 flow of tears was caused by the least trace of sub- 
 stance decomposed. The following day the irritation 
 to the eyes and the mustard oil smell was less 
 noticeable owing, probably, to the fact that the 
 compound is decomposed on standing some time with 
 water. The clear heavy oil obtained, was washed 
 with dilute caustic potash solution to remove acid 
 traces. It was then shaken with distilled water, 
 dried over fused sodium sulphate, and part dried over 
 fused calcium chloride. The principal fraction of the 
 product boiled at 147 C., and as no trace of sulphur 
 could be found by analysis, it was concluded to be 
 tetrachloracetylene. It possessed an ethereal odor 
 like chloroform mixed, however, with traces of the 
 odor of mustard oil. 
 
 When acetylene is passed into the solution or 
 mixture of aluminium chloride and sulphuryl chloride, 
 action takes place almost immediately. Under 
 favorable conditions the dry gas is completely 
 absorbed as fast as it can conveniently be passed into 
 the apparatus. The heat is considerable, and no 
 gaseous products are evolved. If the acetylene 
 leaving the reflux condenser is passed into water, 
 a strong smell of sulphur dioxide is noted. This, 
 however, is due to the decomposition by water of the 
 
- 105 
 
 sulphury 1 chloride carried over mechanically, even 
 through a well cooled condenser. The gas passed 
 into barium chloride, gives rise to an immediate 
 precipitate insoluble in acids, barium sulphate. 
 Moreover, when the action has well started, the 
 reflux condenser may be stopped with a cork, so 
 that no escape for the evolved acetylene is possible. 
 It is still absorbed in a regular stream and without 
 the production of any gaseons product. 
 
 When acetylene is made to react with suphuryl 
 chloride in the presence of aluminium chloride, the 
 principal product has been shown to be an addition 
 product acetylene tetrachloride. No other chloride 
 has been separated by fractional distillation, but 
 there is evidently another compound present that 
 possessed the irritating odors just mentioned. More- 
 over, on heating the acetylene tetrachloride residues, 
 the temperature rose steadily until, at a certain point 
 between 165 C. and 175 C., decomposition set in, 
 accompanied with the separation of carbon and 
 evolution of hydrochloric acid gas. The last frac- 
 tions also gave evidences of the presence of sulphur. 
 In order to isolate the sulphur compound other 
 methods beside that of fractional distillation had to 
 be resorted to. In the action of sulphuryl chloride 
 on various products, other compounds beside chlorides 
 have been obtained, such as sulphones, sulphone 
 chlorides, even in one instance a disulphide. It was 
 
 thought probable that beside tetrachlorethane, a 
 
 /ATT /o/~) rM^ 
 sulphone chloride of the formula A-ripi 
 
 might exist in the products of reaction. This sub- 
 
io6 
 
 substance would bear a relation of acid chloride to 
 acetaldehyde disulphonic acid as ethylidene chloride 
 itself does to acetaldehyde. 
 
 In order to purify the tetrachlorethane obtained 
 from sulphuryl chloride, the compound was driven 
 over by distillation in a current of dry steam. The 
 oil thus obtained lost much of its evil odor, while a 
 semi-solid brownish residue was left in the distilling 
 flask. This product could not be purified sufficiently 
 to be analyzed. It is some what soluble in ether, 
 insoluble in ordinary alcohol, but could not be 
 crystallized in a mixture of ether and alcohol. All 
 attempts, to obtain crystals, or any definite compound 
 failed. The tetrachloracetylene thus purified, boiled 
 at 145 C. 148 C., and posessed a nearly pure odor 
 of chloroform. As the temperature rose above 
 148 C. 150 C., signs of decomposition appeared 
 in the presence of white fumes and separation of 
 carbon. The brownish residue when cooled, de- 
 posited crystals more or less clear. Only a very 
 small amount was obtained. They were recrystallized 
 in a few drops of ether when separated from the oily 
 residue. Analysis gave no trace of sulphur ; they 
 posessed the characteristic camphor-like odor of 
 hexachlorethane. They were formed from the 
 chlorination of tetrachlorethane in the presence of 
 aluminium chloride. 
 
 C 2 H 2 C1 4 +S0 2 C1 2 + A1C1,= C 2 C1 6 + AlCl g *SO 2 + 2HC1. 
 
 Another attempt was made to isolate the sulphur 
 compounds referred to. About seven hundred grams 
 of chemically pure sulphuryl chloride were treated 
 
-107- 
 
 with acetylene in the presence of aluminium chloride 
 in portions of two hundred to two hundred and fifty 
 grams at a time. Aluminium chloride was added 
 during the operation only as fast as it was dissolved 
 by the sulphuryl chloride. It was found that the 
 action ceased when aluminium chloride had been 
 added in the proportion of one part of this compound 
 to every two, or two and half of sulphuryl chloride 
 by weight. 
 
 The products of reaction were united and subjected 
 to distillation on a water-bath under diminished 
 pressure, in order to remove the excess of sulphuryl 
 chloride. About fifty to seventy-five cubic centi- 
 meters of distillate were obtained. Before this dis- 
 tillation the small excess of aluminium chloride had 
 had been removed by filtering through glass-wool. 
 A part of the product of reaction of acetylene on the 
 solution of aluminium chloride and sulphuryl chloride 
 solidified to an amorphous mass on standing several 
 months. 
 
 Under diminished pressure of 58 to 63 cm. , the boil- 
 ing of the contents of the flask began at 15 C. 
 Together with the excess of sulphuryl chloride an 
 oil came over which was afterward found to boil at 
 120 C. under atmospheric pressure. It had the 
 odor of chloroform, or ethylene chloride, and posessed 
 no trace of any disagreeable products. The tempera- 
 ture of the distillation was kept near 80 C. under 
 diminished pressure, and when the product ceased to 
 come over, the operation was interrupted. 
 
 The residue from the distillation under diminished 
 pressure was then decomposed by pouring it into ice- 
 
io8 
 
 water slowly with constant stirring. No violent 
 action took place under these circumstances. An 
 amber-colored oil sank to the bottom of the beaker. 
 It possessed the disagreeable odor already referred to. 
 The oil was distilled in a current of steam, and when 
 the tetrachloracetylene had been driven over, a brown 
 viscous oil was left in the distilling flask. This 
 product became semi-solid on cooling, but it resisted 
 all attempts at purification. It was found to be 
 soluble in ether, and when this was evaporated the 
 mass was left as impure as before. It does not 
 dissolve in alcohol, nor would it crystallize from a 
 mixture of ether and alcohol. 
 
 Distillation in a current of dry steam did not, how- 
 ever, remove the evil smelling product completely 
 from the distillate. The oil in the receiver was 
 thoroughly washed with water, and finally dried over 
 fused sodium sulphate. The product was subjected 
 to fractional distillation, and the greater part came 
 over near 147 C. and proved to be tetrachloracety- 
 lene. Another fraction boiled quite constantly 
 between 160 C. and 163 C. All the fractions, even 
 those with the lowest boiling points, possessed the 
 smell of mustard oil, and sulphur was found in 
 analysis. When decomposition began at 170 C. 
 the operation was stopped. The residue possessed 
 the unbearable odor of allyl mustard oil. 
 
 The oils were at last separately washed with a 
 dilute solution of caustic potash. The solution took on 
 yellowish tint and considerable heat was evolved. 
 Each fraction diminished very much in volume. All 
 the fractions were then separately redistilled and 
 
109 - 
 
 found to have the same boiling point as before. The 
 wash water was evaporated down on a water-bath, 
 and after potassium chloride had come out, an impure 
 salt of a sulphonic acid crystallized out. It was not 
 acetaldehyde disulphonic acid as its oxime could not 
 be prepared. The salt is but slightly soluble in ether 
 which removes all impurities. A very small amount 
 was thus obtained pure by recrystallization from 
 alcohol. Not enough was obtained, however, for 
 analysis. 
 
 The oils after repeated fractional distillation re- 
 mained constant only at the boiling point of tetra- 
 chlorethane. They seemed to be purer than before, 
 but the fractions that came over at higher tempera- 
 tures still possessed the odor of mustard oil. Tetra- 
 chloracetylene could with certitude be shown to be 
 present. The fraction coming over under diminished 
 pressure, as also part of the decomposed oil, both of 
 which products boil very constantly at 120 C. were 
 very probably tetrachlorethylene obtained by decom- 
 position of tetrachloracetylene in the presence of 
 aluminium chloride and sulphuryl chloride with 
 application of heat. 
 
 C 2 H 2 Cl i +S0 2 Cl+AlCl 3 =C 2 CU+2HCl+AlCVSO 2 . 
 
 At 1 60 163 C., a considerable fraction was ob- 
 tained with a remarkably constant boiling point. 
 
 According to the theory of dissociation catalysis 
 advocated by Ruff, it is supposed that sulphuryl 
 chloride is dissociated in the presence of aluminium 
 chloride as represented by the equation. 
 
 AlCl 3 -f S0 2 C1 2 ^= A1C1 3 ' SO 5 + C1 2 . 
 
no 
 
 A solution of aluminium chloride in sulphuryl 
 chloride was put into a flask connected with a well 
 cooled reflux condenser. The latter was in turn 
 connected with a long tube bent at right angles and 
 entering another flask into which acetylene was 
 passed. The last flask was connected with a con- 
 denser and receiver. Twenty-five grams of sulphuryl 
 chloride and twenty grams of aluminium chloride 
 were thus treated to demonstrate the presence of free 
 chlorine. If this gas be given off, it would be shown 
 either by its union, or explosion with acetylene in 
 the second flask. It was found that considerable 
 heat was required before the presence of free chlorine 
 could be detected by its color and odor. A few drops 
 of tetrachloracetylene were obtained from the union 
 of the two gases. By heating the aluminium chloride 
 mixture in the first flask chlorine was freely evolved 
 and met the acetylene in the second flask. Vapors 
 of chloride were effectually kept back by the conden- 
 ser. No explosion was obtained and no precautions 
 were made to avoid one. Acetylene was allowed to 
 enter the apparatus before the chlorine was evolved, 
 contrary to the usual method of bringing the gases 
 together. In the case of acetylene, the first part of 
 the supposed reversible reaction was found to hold 
 good, and the presence of tetrachlorethane is due to 
 the union of acetylene with the dissociated chlorine 
 of the compound, while the sulphur dioxide unites 
 with the aluminium chloride. 
 
 SO 2 C1 2 +A1C1 8 =A1C1 3 -SO 2 +C1 2 , 
 2C1 2 +C 2 H 2 =C 2 H 2 CU. 
 
v^r~E^\ 
 
 UNIVERSITY I 
 
 In order to satisfy myself as to the assumed rever- 
 sibility of the reaction of the dissociation of sulphuryl 
 chloride, I have tried to effect the same experimentally. 
 It appears that in order to demonstrate the fact, the 
 attempt should have been made to unite chlorine 
 with the compound, A1C1 3 *SO 2 to form sulphuryl 
 chloride. 
 
 A1C1 3 'SO 2 +C1 2 =A1C1 3 +SO 2 C1 2 . 
 
 Unless under certain conditions this can be actually 
 effected, it cannot be assumed that the equation is 
 reversible. It was found impossible to effect a reac- 
 tion between chlorine and the compound, A1C1 3 'SO 2 , 
 though it was tried in several ways and under varied 
 conditions. Neither at ordinary temperature nor 
 with the aid of heat have I been able to obtain any 
 sulphuryl chloride. Until sulphuryl chloride shall 
 have been made from the substance, A1C1 3 *SO 2 , and 
 and free chlorine, it does not seem justifiable to 
 postulate the reversible action. 
 
 A1C1 3 +SO 2 C1 2 =A1C1 3 'SO 2 + C1 2 , or, 
 C1 2 +A1C1 3 -SO 2 =A1C1 3 +SO 2 C1 2 . 
 
 Moreover, the theory of Ruff seems just as valid 
 without assuming that the action is reversible. 
 Reversibility is unnecessary to explain the facts. 
 It is sufficient that aluminium chloride dissociates 
 sulphuryl chloride in the presence of a third sub- 
 stance capable of forming a more stable chloride. 
 Under these conditions chlorination will take place 
 often without raising the temperature by external 
 heating. 
 
112 > 
 
 In chlorinating acetylene with sulphuryl chloride 
 in the presence of aluminium chloride, no explosion 
 or spontaneous combustion was ever noted, though 
 no precautions were used in excluding air or direct 
 sunlight. It has been shown that chlorine is present 
 even at ordinary temperatures in the mixture of 
 aluminium chloride and sulphuryl chloride. I have 
 passed a mixture of dry air and acetylene into 
 sulphuryl chloride without noticing explosion or com- 
 bustion. On the contrary, quiet union of acetylene 
 and chlorine resulted, with the formation of tetra- 
 chloride of acetylene. This seems very strange if, 
 according to Mouneyrat, the principal cause of explo- 
 sion of acetylene with free chlorine is to be referred 
 to the presence of oxygen. In view then of this 
 fact, we should be led to conclude that either free 
 chlorine is not present at ordinary temperatures in 
 the aluminium and sulphuryl chloride mixtures, or 
 prior to and independently of the presence of oxygen 
 another cause must operate to initiate the explosion 
 of free chlorine and acetylene when brought together. 
 
 The phenomenon of explosion or spontaneous com- 
 bustion was not found to occur even when the 
 mixture of aluminum chloride and sulphuryl chloride 
 was heated while acetylene was being passed into the 
 flask. The operation was performed on a water- 
 bath so that the contents boiled vigorously. The 
 reflux condenser remained open to the air, and no 
 precautions were made to exclude air. Owing to 
 the heat, signs of decomposition set in as soon as the 
 acetylene was passed into the mixture. The yield 
 of tetrachloracetylene was poor as tarry products 
 
were formed. This was probably due the direct 
 union of sulphuryl chloride with acetylene under 
 these circumstances to form sulphonechlorides of 
 acetylene. 
 
 CHIORINATTON OF ETHYI,ENE WITH SUI^PHURYI, CHLORIDE 
 IN THE PRESENCE OF ALUMINIUM CHLORIDE. 
 
 Ethylene, like acetylene, does not act on sulphuryl 
 chloride alone, at ordinary temperatures. No traces 
 either of chlorides or sulphonechlorides could be thus 
 obtained. If, however, some aluminium chloride be 
 added, absorption slowly takes place. The action 
 can be accelerated by frequent shaking of the mixture. 
 
 The union was effected in a Bulterow's apparatus. 
 The ethylene was made in the usual way, from sul- 
 phuric acid and alcohol. The gas was purified by 
 passing it through strong sulphuric acid and caustic 
 potash solution, and was collected in a gasometer. It 
 was dried by passing it through strong sulphuric acid 
 and a drying cylinder containing fused calcium chlo- 
 ride, and then absorbed in the Butlerow's apparatus 
 containing a solution of aluminium chloride in sul- 
 phuryl chloride. Very little rise in temperature was 
 noticed. After the absorption ceased, the contents 
 were decomposed by pouring them into cold water. 
 An oil was left that had an ethereal odor like chloro- 
 form mingled with traces of the odor of mustard oil. 
 The product was washed with a dilute solution of 
 caustic potash, then with water, and was finally dried 
 over fused calcium chloride. One half of the product 
 distilled on a water-bath, and was afterward found to 
 boil exactly at 83 C. It was very pure and did not 
 
possess the odor of mustard oil. The second fraction 
 had the odor of chloroform, and consisted of a mix- 
 ture of higher boiling chlorides and sulphonechlorides 
 with a very disagreeable odor. Attempts to distill it 
 soon ended by decomposition and charring of the 
 contents of the flask. Acetylene tetrachloride was 
 probably the principal product of the second fraction, 
 as Mouneyrat has shown that ethylene chloride is 
 further chlorinated in the presence of aluminium 
 chloride and free chlorine especially when external 
 heat is applied. In the case in question the chlorine 
 came from sulphuryl chloride present, which further 
 reacted with ethylene chloride according to the 
 reaction. 
 
 C a H 4 +2SO 2 Cl a + 2AlCl 8 =C 2 H a Cl 4 +2HCl+ 
 2A1C1 3 'S0 2 . 
 
 In order, if possible, to separate the substance 
 which possessed the odor of mustard oil, and which 
 was most likely a sulphonechloride of ethylene, about 
 250 grams of sulphuryl chloride were treated in the 
 presence of aluminium chloride with ethylene gas. 
 Aluminium chloride was added in small quantities 
 from time to time only as fast as it was used up in the 
 reaction. Ethylene is not readily absorbed by the 
 mixture, and so it was thought best to aid the action 
 by heating gently on a water-bath. The operation 
 was carried on in a round bottom flask fitted with a 
 reflux condenser. When the gas has been passed 
 through the mixture for some time, the contents of 
 the flask took on a dark color. Towards the close of 
 the action aluminium chloride ceased to be dissolved. 
 
The product was then distilled on a water-bath, and 
 a clear oil came over between 35 and 45 C., under 
 a pressure of 500 mm. This was mostly pure ethy- 
 lene chloride mixed with an excess of sulphuryl 
 chloride. The latter was decomposed with water and 
 the residue when washed, dried, and distilled, was 
 found to boil at exactly 83 C. under atmospheric 
 pressure. The whole liquid came over to the last 
 drop at the boiling point of ethylene chloride. The 
 product remained pure and retained its characteristic 
 pleasant odor for many months, thus showing it to be 
 umixed with any impurities whatever. Unlike ethy- 
 lene chloride made by direct union of the gases it did 
 not become pink colored on standing, neither was a 
 disagreeable odor noticed even after half a year. 
 The method seems well adapted for the rapid prepa- 
 ration of pure ethylene chloride in the laboratory. 
 
 The residue was cooled with ice-water and then 
 decomposed with very cold water. The disagreeable 
 odor was noted as before. A dirty, pasty mass was 
 left, which seemed to indicate the presence of a large 
 quantity of tarry products. It was subjected to dis- 
 tillation on a water-bath, and impure ethylene chlo- 
 ride was obtained. The residue was then heated on 
 a Babo air bath, and signs of decomposition were 
 noticed before the temperature of 150 C. was ob- 
 tained. Hydrochloric acid fumes were given off and 
 carbon separated. After this initial decomposition 
 had ceased, a heavy oil distilled at 200 C. Dense 
 white fumes were evolved from it in presence of moist 
 air. It possessed the odor of mustard oil, and the 
 other characteristics of isethionyl chloride which boils 
 
n6 
 
 at 200 C. It was very very impure, however, and 
 contained empyreumatic products. Chlorsulphone 
 chloride of ethylene was formed according to the 
 reaction. 
 
 _CH 2 S0 2 C1 
 
 AMYI.ENE AND SULPHUR YI, CHLORIDE. 
 
 Though acetylene and ethlene did not react with 
 sulphuryl chloride unless the action be accelerated by 
 means of aluminium chloride, amylene on the contrary 
 reacted directly. When even small quantities of the 
 compounds were brought together, amylene broke 
 up the sulphuryl chloride molecule with almost ex- 
 plosive violence. A few drops of each in a test-tube 
 gave off much heat in union and in a few seconds 
 boiled so strongly as to dash the contents out of the 
 tube. Chlorides of pentane were formed. 
 
 Accordingly, it was found necessary in chlorinating 
 the compound with sulphuryl chloride, to dilute the 
 amylene by dissolving it in twice its weight of chloro- 
 form, and cooling the flask with a freezing mixture. 
 A reflux condenser was attached to the flask contain- 
 ing 50 grams of amylene dissolved in 100 grams of 
 chloroform. About 100 grams of sulphuryl chloride 
 were slowly allowed to enter the flask from a drop- 
 ping funnel. An immediate action took place. When 
 the union was effected rapidly, the contents gave off 
 so much heat as to boil in a freezing mixture, sul- 
 phur dioxide being evolved. Nearly an hour was 
 needed to introduce all the sulphuryl chloride. After 
 the action was completed, the flask was moderately 
 warmed and sulphur dioxide driven out. The con- 
 
tents are distilled on a water-bath, when the excess 
 of chloroform was separated, mixed with a small 
 quantity of sulphuryl chloride. Sulphur dioxide gas 
 remained in solution. The chlorides of amylene were 
 then fractionated. Below the temperature of 130 C. 
 a mixture of chloroform and some amylene chloride 
 distilled. Amylene chloride itself came over from 
 130 C. to 140 C. Trichlorpentane was also formed 
 and went over at higher temperatures together with 
 amylene chloride. The higher boiling fractions 
 possessed the characteristic camphor odor and taste of 
 trichlorpentane. The reactions may be represented 
 as follows : 
 
 C 5 H 10 +S0 2 C1 2 =C 5 H 10 C1 2 +S0 2 . 
 
 C 5 H 10 C1 2 +S0 2 C1 2 =C 5 H 9 C1 3 +HC1+S0 2 . 
 The amylene which was used boiled at 45 C. Both 
 the hydrocarbon and the chloroform were previously 
 dried perfectly with fused calcium chloride. When 
 aluminium chloride was added tarry products were 
 formed, and solids resulted having a rather unpleasant 
 camphor odor, but the yield of amylene chloride itself 
 was not good. No sulphur compounds were noticed 
 when aluminium chloride was not used. The higher 
 fractions underwent partial decomposition in rectifying, 
 carbon was separated and hydrochloric acid was 
 evolved. 
 
 BEHAVIOUR OF ACETYLENE TOWARDS OTHER CHLO- 
 RIDES AND CHLORINATING AGENTS. 
 ACETYLENE AND DlSULPHUR BICHLORIDE. 
 
 When acetylene was passed into disulphur di- 
 chloride kept boiling in a flask with a reflux con- 
 
n8 
 
 denser, the gas was very slowly absorbed. The action, 
 however, was very imperfect. When the product 
 was decomposed with water an organic oil is left in 
 small quantity. It was very impure, mixed with 
 sulphur and possessed a disagreeable alliaceous odor. 
 The precipitate of free sulphur retained this odor for 
 a long time after decomposition with water. When 
 aluminium chloride was added to the disulphur di- 
 chloride into which acetylene had been passed for 
 several days, an immediate and strong reaction took 
 place accompanied by a change of color of the contents 
 of the flask from clear yellowish red to opaque brown. 
 When acetylene was passed into disulphur dichloride 
 in the presence of aluminium chloride, the gas was 
 completely absorbed with the evolution of so much 
 heat that the flask had to be cooled with water, or the 
 flow of gas temporarily diminished to prevent total 
 decomposition of the products formed. Towards the 
 end of the reaction the mixture of disulphur dichlo- 
 ride and aluminium chloride tended to solidify on 
 exposure to the air. Fractional distillation, even 
 under diminished pressure, failed to separate the com- 
 pounds formed. Decomposition took place before a 
 temperature of 140 C. was reached. The first frac- 
 tion of the distillate was of a light straw color, and 
 possessed the characteristics of thiocarbonyl chloride. 
 It fumed strongly in the air. At a temperature of 
 74 C. and 300 mm. pressure it began to distill. The 
 color of the distillate became a darker red between 
 121 C. and 141 C. under 350 mm. pressure. At 
 1 60 C. a beautiful violet colored product distilled, 
 and almost simultaneously decomposition set in with 
 
Or THE" 
 
 UNIVERSITY 
 
 or 
 
 the separation of carbon, sulphur, and hydrocnToric 
 acid. The carbon separated in hard compact form 
 like coke. One of the products of decomposition was 
 a greasy black product which separated with the 
 violet oil above 1 60 C. The oil could not be redistilled 
 under atmospheric pressure without undergoing 
 decomposition. On decomposing the product of re- 
 action a very small quantity of impure acetylene 
 tetrachloride was obtained. When the product of 
 the reaction of acetylene with disulphur dichloride in 
 presence of aluminium chloride was decomposed 
 before distillation by pouring it into well cooled 
 water, acetylene tetrachloride in very impure con- 
 dition mixed with alumina and sulphur, was obtained. 
 
 Guthrie 1 has shown that ethylene forms additional 
 compounds with disulphur dichloride, when the gas 
 was passed into the heated compound. Substances 
 of the formula, C 2 H 4 C1 2 'S 2 C1 2 , and ( C 2 H 4 ) 2 'S 2 C1 2 , 
 were obtained. 
 
 Attempts were made to obtain the similar acety- 
 lene compounds that might be formed by the action 
 of dry acetylene upon aluminium chloride and disul- 
 phur and dichloride. The products of the reaction were 
 decomposed with water, and a solid mass containing 
 sulphur and tetrachlorethane was extracted with 
 several liters of ether, in which the compound is some- 
 what soluble. After evaporating the ether, an oily 
 residue was left that crystallized in radiating needles, 
 slightly tinged with a purple violet. It was mixed 
 
 ijour. Chem. Soc. XIII., 35, 129, XIV., 128. Ann. 113, 
 266, and 1 1 6, 234. 
 
120 
 
 with tetrachlorethane and disulphur dichloride. The 
 crystals could not be purified or separated from 
 the other products. The extract with carbon disul- 
 phide instead of ether, underwent general decompo- 
 sition, carbon, sulphur and hydrochloric acid being 
 the final products. 
 
 ACETYLENE AND SULPHUR DICHLORIDE, (SCla). 
 
 Acetylene was absorbed more readily by sulphur 
 dichloride than by disulphur dichloride, but as the 
 former gave off free chlorine, it was necessary to cool 
 the flask with ice-water and carefully to regulate the 
 stream of acetylene, in order to prevent spontaneous 
 combustion of the escaping gases. By allowing the 
 acetylene to enter the compound through a capillary 
 tube all danger of explosion was obviated. The escap- 
 ing gases were at times spontaneously inflamed at the 
 beginning of the operation. This occurred especially 
 when they were allowed to bubble through water, the 
 gas bubbles then exploding on contact with the air. 
 There was reason to believe that a great part of the 
 acetylene absorbed was not chemically acted upon 
 but only held in solution. When aluminium chloride 
 was added to the contents of the flask after passing in 
 acetylene some hours, a sudden and violent reaction 
 takes place, accompanied with combustion of the 
 evolved gases, and separation of carbon. The residue 
 took on a dark brown color and became very hot. Hydro- 
 chloric acid was slowly evolved. The products of the 
 reaction after adding aluminium chloride and continu- 
 ing the absorption of acetylene were apparently the 
 same as in the case of disulphur dichloride. Frac- 
 
121 
 
 tional distillation even under diminished pressure did 
 not give pure products. More tetrachloracetylene 
 was obtained than in the previous experiment. The 
 study of the action of acetylene upon the chlorides of 
 sulphur will be continued. 
 
 ACETYLENE AND VARIOUS OTHER CHLORIDES. 
 
 (THIONYL CHLORIDE, SOCk). 
 
 Acetylene did not react with thionyl chloride even 
 in the presence of aluminium chloride at oridinary 
 temperature. When the mixture of chlorides was 
 heated while acetylene was passed into the com- 
 pounds, tarry products were obtained possessing a 
 very disagreeable odor like that of the sulphone 
 chlorides of the aromatic series. Small quantities of 
 the products of reaction were obtained as a dark 
 brown gummy mass, on decomposing the contents of 
 the flask with water. 
 
 (STANNIC CHLORIDE, SUCl.4) 
 
 Pure anhydrous redistilled stannic chloride, free 
 from chlorine, did not give up part of its chlorine to 
 acetylene even in the presence of aluminium chloride. 
 When the heat was applied, acetylene was decom- 
 posed in part, leaving hard particles of carbon floating 
 in the liquid, but no chloracetylene was obtained. 
 The stannic chloride boiled at 114 C. and was pure 
 and perfectly anhydrous. 
 
 PLUMBIC CHLORIDE, (PDCfc), AND PLUMBIC AMMONIUM CHLORIDE, 
 (PbCl4,2NH4Cl). 
 
 When acetylene was passed into the solution of 
 plumbic chloride in strong hydrochloric acid, explo- 
 sions took place by reason of the free chlorine 
 
122 
 
 constantly evolved from the compound. Crystalline 
 plumbic ammonium chloride has been found to give 
 up chlorine readily to aromatic hydrocarbons. Acety- 
 lene, however, gave no chlorine reaction products 
 even in presence of aluminium chloride, nor when 
 both chlorides were dissolved in another liquid chlo- 
 ride, such as phosphorus trichloride. When calcium 
 carbide is heated with plumbic ammonium chloride, 
 a violent reaction takes place, but no acetylene 
 chloride was obtained. The products seemed to be 
 similar to those made by Salvador! 1 by the action of 
 ammonium chloride on calcium carbide. As no 
 acetylene chloride was obtained, the action of acety- 
 lene with plumbic chloride was not further investi- 
 gated. 
 
 CARBONYL CHLORIDE (COCls), CYANOGEN CHLORIDE (CUCl), NITROSYL 
 CHLORIDE (NOCl). 
 
 None of these gases showed any reaction whatever 
 with acetylene. Carbonyl chloride and nitrosyl chlo- 
 ride were also passed with acetylene over aluminium 
 chloride without any signs of union. The latter in 
 the nascent condition evolved from nitrosulphonic 
 acid, sodium chloride, and sulphuric acid failed to 
 give any organic compound when acetylene was 
 passed into the mixture. 
 
 ANTIMONY TRICHLORIDE, (sbcls), AND PHOSPHORUS PENTACHLORIDE, 
 (PCl6), 
 
 When antimony trichloride and aluminium chloride 
 were heated together while acetylene was passed over 
 the compounds, only traces of tarry products were 
 
 i Gaz. XXXII., II., 496, ( 1902). 
 
- 123- 
 
 obtained possessing very disagreeable odors. Phos- 
 phorus pentachloride did not give up part of its 
 chlorine to acetylene even in the presence of alumi- 
 nium chloride. When a solution of phosphorus 
 pentachloride and aluminium chloride in phosphorus 
 trichloride was heated below the dissociating point of 
 phosphorus pentachloride while acetylene was passed 
 into the boiling mixture, no better results were ob- 
 tained. Only traces of ill-smelling organic compounds 
 were found on decomposing the product of reaction. 
 When phosphorus pentachloride was further heated, it 
 dissociated. Explosions took place whenever acety- 
 lene was passed over it at higher temperatures. 
 
 CHROMYL CHLORIDE, (CrO2Cl2). 
 
 As this compound gives off free chlorine very 
 readily, and is likewise a powerful oxydizing agent, 
 violent explosions would be expected when acetylene 
 is passed into chromyl chloride. In fact, every 
 attempt to introduce acetylene into the flask contain- 
 ing this substance ended in an explosion or spon- 
 taneous combustion of the gas and separation of 
 carbon. 
 
 ARSENIC TRICHLORIDE, (ASCla). 
 
 Pure arsenic trichloride free from oxide did not 
 show any reaction with perfectly dry acetylene. 
 When aluminium chloride was added the absorption 
 of the gas was effected with the evolution of consider- 
 able heat. The contents of the flask turned black. 
 When decomposed by pouring the substance into cold 
 water, a black gummy mass separated out, and on 
 standing for some time crystals appeared in the aqueous 
 solution. The tarry substance possessed a most 
 
- I2 4 
 
 nauseating and penetrating odor, and was extremely 
 poisonous. Inhalation of the fumes, even in small 
 quantity caused nervous depression. No chlorine 
 derivatives of acetylene were noted. Owing to the 
 poisonous nature of the compounds formed, their 
 thorough investigation was postponed. 
 
 ACETYLENE AND DRY IODINE TRICHLORIDE, (ids). 
 
 The action of acetylene upon iodine trichloride in 
 solution of strong hydrochloric acid was studied by 
 Plimpton and Sabanejef. Monochlormoniodacetylene 
 was formed. Chloriodacetylenes were formed with 
 more than one atom of chlorine in the molecule and 
 could not be distilled, as they decomposed with the 
 separation of iodine at 1 20 C. 
 
 To obtain the crystals of iodine trichloride, iodine 
 was heated in a retort while a stream of dry chlorine 
 was passed into the vapor. Connected with the retort 
 was a flask with two ground glass openings. The 
 neck of the retort was fitted into one of these so that 
 it was not necessary to use rubber or cork connec- 
 tions. The trichloride was sublimed into the fiask 
 in a stream of dry chlorine, care being taken that no 
 iodine monochloride was allowed to pass over. When 
 all the trichloride was sublimed into the receiver 
 chlorine was passed for some time to get rid of the 
 traces of monochloride of iodine. The well-stopped 
 receiver containing the iodine trichloride in an atmo- 
 sphere of chlorine was then put aside for twenty-four 
 hours. 
 
 Acetylene was then passed in through one of the 
 openings by means of a capillary tube. The gas was 
 absorbed as fast as it entered, and more acetylene was 
 
- 125 
 
 drawn in by reason of the vacuum created by absorp- 
 tion, as the other opening of the flask was kept 
 closed with a cork. The heat evolved in the reaction 
 was considerable, and the flask was cooled by a stream 
 of cold water. The first stage of reaction seemed to 
 be that of chlorination, as iodine monochloride was 
 separated as soon as the acetylene entered. No ex- 
 plosion occurred. As soon as all the iodine trichlo- 
 ride had disappeared, the operation was immediately 
 interrupted, and the free iodine and iodine mono- 
 chloride removed from the oil which was then clear 
 and odorless. The dried product was distilled. 
 Very little distillate was obtained below 126 C. 
 The temperature then rose to 146 C., when much 
 iodine separated and the greater part of the oil dis- 
 tilled over. Monochlormoniodacetylene boiled be- 
 tween 1 1 6 and 119 C. And therefore, little if any 
 was present. Acetylene tetrachloride was the principal 
 or at least the first product of reaction between 
 acetylene and dry iodine trichloride. Chloriodacety- 
 lene was the result of a secondary reaction. The fact 
 that iodine monochloride comes out as soon as 
 acetylene reacted with the solid trichloride of iodine, 
 sufficiently demonstrated this. The trichloride of 
 iodine then, acted as a chlorinating agent, and when 
 the operation was interrupted after all the trichloride 
 of iodine was used up, very little if any acetylene 
 iodochloride, C 2 H 2 C1I, was obtained. The reaction 
 may be represented as follows : 
 
 l a = C a H a Cl 4 +2lCl. 
 
 When an excess of acetylene is present, the iodine 
 
126 
 
 monochloride reacted further with the hydrocarbon to 
 form monochlormoniodacteylene according to the 
 reaction : 
 
 C 2 H 2 -fICl = C 2 H 2 ICl. 
 
 Other reactions forming compounds of acetylene 
 with chlorine and iodine containing more than one 
 atom of chlorine took place independently of those 
 referred to. It is also noteworthy that a compound as 
 easily dissociated as iodine trichloride in the dry 
 state does not explode with acetylene. 
 
 ACETYLENE AND " AQUA REGIA." 
 
 The chlorinating action of ' ' aqua regia ' ' is said to 
 be due to the evolution of chlorine in the nascent 
 state when the mixture is warmed, and this effect is 
 produced according to the reaction : 
 
 3 HC1+HNO 3 =2H 2 0+NOC1+C1 2 . 
 
 When acetylene was passed into * ' aqua regia ' ' at 
 ordinary temperature or even at the boiling point of 
 the solution, no explosion or spontaneous combustion 
 was ever observed, though air was present during 
 the operation. The gas was passed into the acids 
 both in a slow and rapid stream. Evident signs of 
 reaction were noted by the formation of an oil in 
 small quantity. Even the small quantity that was 
 formed seemed to be decomposed by the continued 
 action of the "aqua regia." The presence of hexa- 
 chlorethane was observed. Small acicular crystals 
 of this compound floated in the acids, but the yield 
 of tetrachlorethane and hexachlorethane was very 
 small. The latter compound resulted from the con- 
 
- 127- 
 
 tinued action of nascent chlorine on the tetrachloride 
 of acetylene when the latter was not immediately 
 removed from the scene of action by distillation. 
 The reaction may be expressed as follows : 
 
 3 HCH-HN0 3 =H 2 O+NOC1+C1 2 , 
 
 2C1 2 +C 2 H 2 =C 2 H 2 C1 4 , 
 C a H a Cl 4 +2Cl a =C 2 C1+2HC1. 
 
 When dry hydrochloric acid gas were passed into 
 fuming nitric acid, no chlorine derivatives of acety- 
 lene were obtained. Nitro-compounds of acetylene 
 were obtained when the acid was diluted with water. 1 
 
 When very strong hydrochloric acid (Sp. gr. 1.20) 
 was boiled with strong nitric acid while a rapid stream 
 of acetylene was passed into the flask connected with 
 a L,iebig condenser, tetrachloracetylene was obtained 
 in greater quantity. It contained, however, as an 
 impurity a nitrogen compound with a penetrating 
 odor which caused a painful flow of tears. Its solu- 
 tion in the oil gave to the latter a pale green color. 
 
 So strong a reagent as ' * aqua regia ' ' did not cause 
 any explosion with acetylene though free chlorine was 
 present. Moreover, air was present in all these 
 experiments and not the slightest trace of carbon was 
 separated. When nascent acetylene was used, reac- 
 tions with " aqua regia" gave the same results, tetra- 
 chlorethane and hexachlorethane being obtained. 
 This was accomplished by throwing pieces of calcium 
 carbide into the acid. Calcium carbide decomposed 
 
 l Gaz. XXXII., I., 202, (1902). Gaz. XXXI., II., 465, 
 (1901). 
 
128 
 
 rather slowly in the mixture, and hexachlorethane 
 was the principal product. In this case no spontaneous 
 combustion or explosion resulted, though very much 
 heat was evolved from the decomposition of the cal- 
 cium carbide. 
 
 ACETYLENE AND ANTIMONY PENTACH^ORIDE, (sbc! 5 ) . 
 
 The method of preparing tetrachlorethane by means 
 of antimony pentachloride and acetylene, discovered 
 by Berthelot and Jungfleisch 1 in 1872, might be con- 
 sidered a more or less convenient way of preparing 
 that compound. When acetylene was passed into 
 antimony pentachloride, the gas was more or less 
 readily absorbed, varying with certain conditions not 
 as yet well determined. On cooling the contents of 
 the flask crystals of the compound, SbCl 3 'C 2 H 2 Cl 2 , 
 separated out When these were heated, a mixture 
 of tetrachloracetylene was supposed to be formed 
 according to the reactions : 
 
 C 2 H 2 +SbCl 5 :=SbCl 3 -C 2 H 2 Cl 2 , 
 
 SbCl 3 'C 2 H 2 Cl 2 =C 2 H 2 Cl 2 +SbCl 3 , 
 
 SbCl 3 'C 2 H 2 Cl 2 +SbCl 5 =C 2 H 2 Cl 4 +2SbCl 3 . 
 
 If the compound of acetylene and antimony penta- 
 chloride be heated with an excess of antimony penta- 
 chloride, tetrachlorethane alone was obtained. 
 
 Sabanejef , 2 eleven years later, repeated this work 
 and obtained very unsatisfactory results^ He com- 
 plained that the absorption took place slowly and 
 
 1 Ann. Chim. Phys. 26, 473, (1872). Carb. D'Hyd. I., 311. 
 
 2 Ann. 216, 261. 
 
129 
 
 with difficulty, that very little heat was evolved, and 
 that explosions often occurred on shaking. He did 
 not succeed in obtaining the crystalline compound 
 mentioned by Berthelot although he had passed the 
 acetylene into the antimony pentachloride for a con- 
 siderable time. 
 
 I have repeated the experiments of Berthelot and 
 Jungfleisch and have come to the same conclusions. 
 Generally, antimony pentachloride absorbed acety- 
 lene quite readily, but at times, for some unknown 
 reason, the action at the beginning of the experiment 
 was remarkably slow. I have not found any good 
 cause for the fact. If, however, the contents of the 
 flask be allowed to stand for a day after passing 
 the gas the subsequent action is quite energetic. 
 This fact would seem to show that acetylene is dis- 
 solved only in part, that it is not chemically combined, 
 but that combination results on standing for some 
 time. On one occasion acetylene gas was passed for 
 a whole day into the antimony pentachloride with 
 very little result. The next day the gas was again 
 allowed to pass into the compound, and the action 
 was so energetic that it was deemed advisable to cool 
 the flask with water during absorption. This heat 
 was evolved within fifteen minutes from the time 
 that the gas was allowed to enter the apparatus. 
 
 The method of Berthelot and Jungfleisch for the 
 preparation of tetrachlorethane, consisted in the dis- 
 tillation of the compound of antimony pentachloride 
 and acetylene, SbCl 3 'C 2 H 2 Cl 2 , with an excess of 
 antimony pentachloride. Two molecules of antimony 
 pentachloride gave up four atoms of chlorine with 
 
- 130 ~ 
 
 the formation of tetrachlorethane. This process 
 involved the use of much antimony compound in 
 order to prepare a small quantity of acetylene tetra- 
 chloride. If, instead of distilling the compound, 
 SbCl 3 'C 2 H 2 Cl 2 , with one molecule of antimony 
 pentachloride, dry chlorine gas was passed into the 
 contents of the flask after previously driving out the 
 gaseous or undissolved acetylene by means of a blast 
 of dry air, the same result could be effected. No 
 explosion took place and the chlorine gas was absorbed 
 with great avidity, and the evolution of so much 
 heat that the flask had to be cooled. The compound, 
 SbCl 3 'C 2 H 2 Cl 2 , took up two molecules of chlorine 
 gas, forming tetrachloracetylene and leaving anti- 
 mony pentachloride according to the reaction : 
 
 SbCl 3 -C 2 H 2 Cl 2 +2Cl 2 =C 2 H 2 Cl 4 +SbCl 5 . 
 
 Now as antimony pentachloride was again present in 
 the solution, acetylene could be passed into the flask 
 after driving out the excess of uncombined chlorine 
 by ' means of dry air or some other inert gas. The 
 process of alternately passing the two gases into the 
 compound could be carried on indefinitely Instead 
 of using the antimony pentachloride as a reagent, it 
 was used rather in the function of "carrier," the 
 same amount of substance being used indefinitely, or 
 even for several separate experiments. It could be 
 obtained unchanged at the end of the operation by 
 distilling off the tetrachlorethane. 
 
 The absorption of chlorine was so rapid and per- 
 fect, that if the exit-tube be closed, the air was drawn 
 through the safety tube in the chlorine generating 
 
flask, by the diminished pressure due to the rapid 
 absorption of chlorine. Moreover, when the acety- 
 lene had been passed alternately several times, its 
 rate of absorption was also improved, and great heat 
 was given off to the reaction. No explosion occurred 
 when the excess of one gas was driven out before 
 passing the other into the apparatus. No more than 
 five minutes was necessary to effect this. When the 
 the absorption of either gas was not allowed to pro- 
 ceed to complete saturation, so that no uncombined 
 gas was present in solution, it was not even necessary 
 to resort to the precaution of using a blast of air to 
 drive out the gas last absorbed. This point of 
 saturation was easily determined by the fact that 
 heat ceased to be evolved when absorption no longer 
 took place. 
 
 In one experiment twenty-five grams of antimony 
 pentachloride were treated as above described. A 
 flask with a reflux condenser was used. The latter, 
 however, was not strictly necessary as the products 
 of reaction are not very volatile. A tube bent at 
 right angles was connected with two T- tubes and 
 stop-cocks to admit the gas alternately, likewise one 
 connection with air from blast. The air was dried 
 by passing through a cylinder containing fused cal- 
 cium chloride. The acetylene was dried by passing 
 through a wash -bottle containing strong sulphuric acid 
 and thence through a drying cylinder containing cal- 
 cium carbide. The tube bent at right angles through 
 which the gases were introduced into the absorption 
 flask, was drawn out of the liquid before passing each 
 gas, so that in case the previous gas were not perfectly 
 
- 132 - 
 
 eliminated by the air-blast, no loss of substance would 
 be sustained by the slight explosion that might occur, 
 forcing the contents back by the concussion. Explo- 
 sions only occurred when either gas was passed in 
 longer than necessary, that is, after it ceased to be 
 absorbed. Dissolved uncombined gases were with 
 difficulty removed. Chlorine could however, be 
 removed by adding a small quantity of antimony 
 trichloride, and acetylene with antimony pentachlo- 
 ride, if one could not wait until the gases were driven 
 out with the air-blast. Only when changing the gases, 
 and then only when not perfectly eliminated did the 
 introduction of one or the other, cause slight 
 explosion. 
 
 In the experiment in question, after passing the 
 acetylene and chlorine alternately several times, the 
 net increase in weight amounted to forty-six grams. 
 The product was distilled, and pure tetrachlore thane 
 obtained. No trace of dichloracetylene, C 2 H 2 C1 2 , 
 was found. No impurities were present after the 
 distillate had been washed with strong hydrochloric 
 acid and water. The product was washed with 
 hydrochloric acid in order to remove a small quantity 
 of antimony pentachloride that came over in the 
 distillation. The oil was dried over fused calcium 
 chloride and possessed the odor of chloroform. It 
 had the correct boiling point of tetrachlore thane. 
 
 Another experiment was performed with two 
 hundred grams of antimony pentachloride. The 
 operation was continued until a net increase of 840 
 grams was obtained from the initial 200 grams of 
 antimony pentachloride. It was not deemed advis- 
 
133 
 
 able to allow the operation to go so far, as it became 
 more difficult to obtain good action when the anti- 
 mony pentachloride was diluted with four times its 
 weight of tetrachlorethane. It was also more difficult 
 to drive out the acetylene gas which tended to 
 dissolve in great quantity in the tetrachlorethane 
 without entering into chemical combination. The 
 alternating action, however, seemed to go on 
 indefinitely. 
 
 According to the method of preparing tetrachlor- 
 ethane proposed by Berthelot and Jungfleisch, explo- 
 sions were not altogether eliminated. I have not had 
 explosions except when the gases were changed, and 
 then very rarely. When one gas was carefully drawn 
 out before introducing the other, no explosion ever 
 took place. ( The perfect elimination of gas with a 
 blast of air became difficult only when the increase 
 of weight was great, owing to the state of dilution of 
 the antimony pentachloride.) When the product 
 was finally to be distilled, chlorine was passed into 
 the solution for the last time. Explosions were thus 
 avoided which are due to the separation of free 
 acetylene in the presence of free chlorine. 
 
 In the distillation some antimony pentachloride 
 passed over with the tetrachlorethane. This was 
 removed with strong hydrochloric acid. Nitric acid 
 did not insure so pure a product. The oil was next 
 washed with water to free it from hydrochloric acid. 
 It was then dried with fused calcium chloride and 
 redistilled. The distillate possessed a constant boil- 
 ing point to the last few drops within the frac- 
 tion of a degree and was clear colorless 
 
-134- 
 
 oil with pure odor. No traces of acid fumes or 
 unpleasant odors were noticed when the products had 
 been sufficiently dried. Acetylene tetrachloride could 
 thus be formed in any desirable quantity. By using 
 larger quantities of antimony pentachloride at the 
 start, even a more perfect action could be obtained, 
 as the heat of the mass-reation greatly promotes 
 absorption. In fact the two gases could be passed 
 simultaneously into a suitable vessel provided they 
 did not come in contact in the gaseous state. 
 
 Instead of distilling off the tetrachlorethane, the 
 contents of the flask may be decomposed in water. 
 A white precipitate is thrown down, which is prob- 
 ably a compound of acetylene chloride with antimony 
 chloride or oxy chloride, or the crystals of the com- 
 pound, SbCl 3 'C 2 H 2 Cl 2 , insoluble in water. These 
 are treated with strong hydrochloric acid to remove 
 the antimony when the oil reappears. After washing 
 several times with hydrochloric acid, and shaking 
 the oil well in a separating funnel with hydrochloric 
 acid, the tetrachlorethane is washed with water, 
 dried, and distilled. 
 
 Berthelot and Jungfleisch seemed to have been of 
 the opinion that the product of the reaction of acety- 
 lene upon antimony pentachloride was decomposed 
 by water. 1 The product of the reaction of acetylene 
 upon antimony pentachloride was not destroyed by 
 water. As soon as it was poured into water, a heavy 
 precipitate was thrown down that is not the oxychlo- 
 
 1 Ann. Chim. Phys. 4, XXVI., (1872). Carb. D'Hyd. I., 
 312. 
 
135 
 
 ride of antimony, but a compound of acetylene 
 tetrachloride and antimony chloride, or oxychloride. 
 As I have already stated, tetrachlorethane can be 
 obtained from it by treating it with strong acids. 
 Even when the product obtained by the continued 
 action of chlorine and acetylene upon antimony 
 pentachloride was decomposed, no oil was separated 
 on pouring into water, but a heavy precipitate came 
 out. Whether this be the compound, SbCVC 2 H 2 Cl, 
 referred to by the authors, I have not as yet been 
 able to ascertain with absolute certainty. 
 
 The precipitate could be dried in a dessicator, 
 and when subsequently treated with acids gave 
 back the oil. Moreover, the precipitate dissolved 
 in ether, alcohol, or a mixture of ether and 
 alcohol, becoming a clear solution with a gray 
 fluorescence. Antimony oxychloride will not dis- 
 solve in these solvents. The ethereal .solution of the 
 compound was evaporated to a small volume and 
 crystals reappeared. When chlorine was passed over 
 them, they appeared to absorb it with the evolution 
 of heat, so that the process of chlorination could be 
 continued with the product supposed by Berthelot to 
 be decomposed in water. This fact let to the opinion 
 that the precipitate formed when the product of 
 reaction of acetylene upon antimony pentachloride 
 was poured into water, was not a decomposition 
 product, but a definite compound of acetylene with 
 antimony chloride in an amorphous state. It was the 
 undecomposed product of union between acetylene 
 and antimony pentachloride from which tetrachlor- 
 ethane was easily recovered with strong acids. In fact 
 
 OF THE 
 
 UNIVERSITY 
 
-136 
 
 the compound was simply precipitated, not decom- 
 posed by water. When attempts were made to dry 
 it for analysis, it continued to give off vapors of 
 tetrachloracetylene and could not be dried to constant 
 weight. 
 
 A simple method of preparing any desirable 
 quantity, has been developed in this laboratory. 
 Dry acetylene is passed into antimony pentachloride 
 contained in a flask with a two-holed stopper. The 
 gas is brought into the flask through a tube bent at 
 right angles and dipping below the liquid. The 
 excess of gas escaped by another tube. No reflux 
 condenser is necessary. When the antimony penta- 
 chloride is nearly saturated with acetylene, the excess 
 of free gas is either blown out with dry air, or in 
 drrwn through by aspiration. Chlorine is then 
 passed into the flask, until the heat of reaction ceases 
 when acetylene is again introduced after removing 
 any free chloride gas present. This process is con- 
 tinued until the net increase in weight amounts to 
 three times the weight of antimony pentachloride 
 used at the beginning of the experiment. The pro- 
 duct is distilled, the distillate washed with strong 
 hydrochloric acid to remove antimony compounds 
 from the oil, then washed with water to remove the 
 acid. It is then dried with fused calcium chloride or 
 sodium sulphate, and redistilled, when pure tetra- 
 chlorethane is obtained. 
 
 According to the method of preparing tetrachlor- 
 ethane proposed by Berthelot and Jungfleisch, only 
 eight parts of acetylene can be absorbed by every 
 hundred parts of antimony pentachloride by weight 
 
137 
 
 when the operation must be interrupted. Accordingly 
 in the experiment described, twenty grams of anti- 
 mony pentachloride would give an increase of only 
 two grams, yielding seven grams of tetrachlorethane. 
 I obtained forty-one grams increase after passing the 
 two gases alternately several times, and over fifty 
 grams of pure tetrachlorethane resulted. Likewise, 
 though according to Berthelot's method, 200 grams 
 of antimony pentachloride should give only 1 8 grams 
 increase in weight, with the subsequent yield of fifty 
 four grains of tetrachloracetylene, I have obtained a 
 net increase of eight hundred and forty grams which 
 corresponds nearly to a kilogram of tetrachloracety- 
 lene, before the operation was discontinued. 
 
-138- 
 
 RE ACTION OF ACETYLENE WITH ACIDIFIED 
 MERCURIC FLUORIDE 
 
 Acetylene forms two series of compounds with salts 
 of mercury. Carbides are combinations of carbon 
 with a metal, and mercury, like some of the other 
 heavy metals gives a carbide when alkaline solutions 
 of its salts are treated with acetylene. The carbides 
 are generally explosive and on treatment with acids 
 give off acetylene. The other series of acetylene 
 compounds of mercury are not generally explosive, 
 and do not give off acetylene with dilute acids but 
 evolve acetaldehyde when heated in acids. Moreover, 
 whereas the carbides give di-iodacetylene and tetra- 
 iodoethylene when treated with iodine, the non- 
 explosive products obtained from acid or neutral 
 solutions of salts generally appear to yield iodoform. 
 They have been characterized as substituted alde- 
 hydes or alcohols, and they contain the metal or an 
 acid-radicle with the metal in the place of one or 
 more of the hydrogen atoms of the organic compound. 
 
 The vinyl derivatives of mercury have been exten- 
 sively studied by Polleck and Thiimmel. 1 They gave 
 off acetaldehyde when attempts were made to obtain 
 free vinyl alcohol in a pure state. 
 
 In 1866, Berthelot 2 first obtained the carbide of 
 mercury resulting from the action of acetylene on an 
 alkaline solution of a mercury salt. He did not, 
 
 J Ber. 22, (1889), 2863. 
 
 2 Ann. Chim. Phys. 4, 9, 386. 
 
- 139 
 
 however, analyze the product at the time though he 
 noticed its explosive properties. The acetylide was 
 made by passing the acetylene into a solution of 
 mercuric iodide in potassium iodide made alkaline 
 with ammonia. 
 
 Basset 1 obtained the same compound from Nessler's 
 solution, but his acetylene appeared to have been im- 
 pure. He ascribed to it the formula, C 2 H,HgI.,HgO. 
 
 Keiser 2 repeated the experiment of Basset with pure 
 acetylene and his results indicated that the product of 
 the reaction of the gas upon the solution of mercuric 
 iodide and potassium iodide in potassium hydroxide, 
 had the formula, C 2 Hg, and is perfectly analogous to 
 the carbides of the other metals, such as silver or 
 copper. 
 
 In 1892, Plimpton 3 published a preliminary notice 
 of his work upon this compound, but it was not until 
 1894 tnat an extended study of the subject was 
 completed. In 1894, Travers and Plimpton 4 had pre- 
 pared the explosive carbide of mercury in a number 
 of others ways. In reference to Keiser 's work 
 they intimated that they could not obtain the 
 silver compound free from water, and they gave it 
 the formula, 3C 2 Hg.H 2 O. 
 
 A series of quite different compounds was obtained 
 when acetylene was passed into acid or neutral solu- 
 tion. Kutscherow, 5 in 1883, noticed that allylene 
 
 1 Zeit. f. Chim. (1869), 314, and Chem. News, 19, 28. 
 
 2 Amer. Chem. Jour. 15, 535. 
 
 3 Proc. Roy. Soc. ( 1894). 
 
 4 Chem. News, 69, 81 and 82, i Cent. (1894), 549. 
 
 5 Ber. 17, 13. 
 
140 
 
 and acetylene passed into mercuric chloride gave 
 precipitates. He analyzed the allylene product but 
 does not seem to have made an analysis of the acety- 
 lene derivative. Pera toner 1 gave it the formula, 
 C 2 H 2 , 3 HgCl 2 ,HgO. 
 
 Keiser, 2 however, obtained different results. He 
 found that the compound contained mercurous mer- 
 cury and that calomel was a product of decomposition 
 on heating. Though not able to separate all the 
 water, he claimed that its composition is represented 
 by the formula, C 2 (HgCl) 2 , or as he also gives it, 
 
 Plimpton 3 had obtained an inexplosive compound 
 by treating mercuric acetate with acetylene. A white 
 precipitate was obtained that turns gray towards the 
 end of the precipitation. The composition of the 
 compound was held to be 3HgO.2C 2 H 2 , and the 
 author claimed to be analogous to the allylene com- 
 pound obtained by Kutscherow 3HgO, 2C 3 H 4 , 2HgCl 2 . 
 lodoform was obtained with iodine and aldehyde 
 with dilute acids. 
 
 Berge and Reychler* had intimated that acetylene 
 was not absorbed by an acid solution of mercuric 
 chloride, and that accordingly this could be used to 
 purify acetylene. 
 
 Biginelli 5 proved that acetylene was absorbed by 
 Berge and Reychler's solution with the formation of 
 
 1 Gaz. XXIV., II., (1894), p. 42. 
 
 2 Amer. Chem. Jour. 15, 535. 
 
 8 Proc. Chem. Soc. (1892), 109. 
 
 4 Bull. Soc. Chim. 3, 17, 218. 
 
 * Ann. di Farm, e Chim. (1898), 16. Cent. (1898), 925. 
 
the definite compound Cl:CH(HgCl), and from this 
 other substances could be obtained by various reac- 
 tions. It gave aldehyde when heated in dilute acid 
 solution. 
 
 Hofman 1 in 1898, obtained from acidified mercuric 
 nitrate, a substance of the composition, C 2 Hg 2 NO 4 H. 
 As he obtained the same substance by the action of 
 acetaldehyde on acid mercuric nitrate, he gave the 
 acetylene compound the constitutional formula, 
 C(Hg)(HgNO 3 )CHO, so that he considered it a sub- 
 stituted aldehyde. He showed that it contained the 
 nitrate group and that it gave aldehyde with dilute 
 acids. 
 
 Erdman and Kothner 2 tried the action of acetylene 
 on mercurous nitrate, and obtained a compound of 
 the formula, C 2 (Hg 3 NO 3 ) + H 2 O. They also suc- 
 ceeded in obtaining a method for the continuous 
 preparation of aldehyde from acetylene by passing 
 the gas into a boiling solution of sulphuric acid to 
 which mercuric oxide or a mercury salt has been 
 added. Kothner 3 referred to the fact that he had 
 obtained a compound of acetylene with mercuric 
 nitrate, and had given it the formula, C 2 Hg 3 NO 4 H 2 , 
 or as it was afterwards shown to be, HgC:CHg-|- 
 HgNO 3 -f H 2 O. He claimed, moreover, to have 
 shown its relation to acetaldehyde and vinyl alcohol, 
 before the article of Hofman had appeared. 
 
 Hofman* criticised Erdman and Kothner 's work on 
 
 1 Ber. 31, 2475. 
 
 2 Zeit. An. Chem. 18, 48. 
 
 3 Ber. 31, 2475. 
 * Ber. 31, 2783. 
 
142 
 
 the ground that, if they had known the relation of 
 the mercury compound to acetaldehyde, they would 
 not have given it an acetylide formula. Hofman 
 claimed that the product of acetylene with acidified 
 mercuric nitrate was neither an acetylide nor a 
 mercurous compound, but a substituted aldehyde. 
 He repeated some of his previous experiments with 
 the same results that he had obtained before, and he 
 gave the compound the aldehyde formula : 
 
 NO,Hg H 
 
 I have attempted to prepare, among others, the 
 fluoride of acetylene and mercury by passing the gas 
 into an acidified solution of mercuric fluoride. 
 Freshly precipitated mercuric oxide was dissolved in 
 cold concentrated hydrofluoric acid. The oxide dis- 
 solves readily with the evolution of heat when the 
 vessel is shaken so that it is necessary to cool the 
 beaker. All the glass apparatus used was well coated 
 with paraffine to prevent corrosion, and also in order 
 to prevent the subsequent introduction of silica as an 
 impurity in the precipitated mercury fluoride of 
 acetylene. When no more mercuric oxide dissolved 
 in the acid, a stream of acetylene was passed into the 
 clear filtered solution. A white flaky precipitate was 
 immediately formed. At a certain stage of the reac- 
 tion the precipitate began suddenly and quickly to 
 turn grayish or bluish white. In order to obtain the 
 white compound free from the gray precipitate the 
 mixture was filtered every few minutes until the 
 product began to change. The stream of gas was 
 
then continued until the precipitation ceased. Both 
 compounds were separately washed with strong hy- 
 drofluoric acid. They were then washed with 
 alcohol to remove water and finally with ether to 
 take out any alcohol remaining. The compounds 
 were then dried over sulphuric acid in a dessicator 
 for several weeks to a constant weight. The white 
 compound is somewhat soluble in strong hydrofluoric 
 acid, insoluble in water, alcohol, or ether. It is a 
 light white powder resembling the product of the 
 action of acetylene on neutral mercuric chloride, 
 C 2 (HgCl) 2 , examined by Keiser. 
 
 ANALYSIS OF THE WHITE PRECIPITATE- 
 
 .4834 grams of substance gave .4739 grams of 
 Mercuric Sulphide. 
 
 .6435 grams of substance gave .6298 grams of 
 Mercuric Sulphide. 
 
 PERCENTAGE OF MERCURY. 
 
 Calculated for C 2 (HgCl) 2 , Found 
 
 Hg. 82.2 I. 82.7 
 
 II. 82.4 
 
 The gray compound resulted from the continued 
 action of acetylene on acidified mercuric fluoride. 
 It resembled in nearly every respect the white com- 
 pound. Towards the end of the reaction free 
 acetaldehyde was present. 
 
ANAI,YSIS OF THE GRAY PRECIPITATE. 
 
 .4834 grams of the compound gave .4041 grams of 
 Mercuric Sulphide. 
 
 .6435 grams of the compound gave .6298 grams of 
 Mercuric Sulphide. 
 
 Calculated for 
 
 Hg. 83 3 I. 83.6 
 
 II.-S4.3 
 
 These compounds are insoluble in dilute acids, and 
 soluble in warm concentrated nitric acids with the 
 formation of mercurous nitrate. Caustic potash pre- 
 cipitates from the diluted nitric acid solution 
 mercurous oxide. When hydrogen sulphide is 
 passed into the compounds suspended in water, they 
 turn black and acetaldehyde and thioaldehyde are 
 formed. Acetaldehyde and thioaldehyde are also 
 formed when the substances are treated with am- 
 monium sulphide, and then neutralized with 
 hydrochloric acid. With concentrated hydrochloric 
 acid a strong reaction takes place with the evolution 
 of hydrofluoric acid, and the formation of the com- 
 pound, C 2 (HgCl) 2 , analyzed by Keiser. 
 
 C 2 (H g F) 2 +2HCl=C 2 (HgCl) 2 +2HF. 
 
 Dry bromine reacts so energetically with the sub- 
 stance that the latter is carbonized on contact. 
 Bromine water gives rise to traces of an oil that is 
 probably bromoform, or bromacetylene. Dry chlo- 
 rine also decomposes the mercury acetylene fluoride 
 with the evolution of much heat, and the formation 
 
H5 
 
 of a small amount of oil. The products resulting 
 from the action of bromine and chlorine have not 
 been carefully studied. A solution of iodine and 
 potassium iodide gives rise to iodoform. A better 
 yield of iodoform is obtained by boiling the com- 
 pound with iodine and sodium carbonate. The 
 iodoform was very pure and after its first crystal- 
 ization from alcohol melted exactly at ii9C. 
 
 The acetylene compound of mercuric fluoride 
 dissolves in chloric acid, or potassium chlorate and 
 hydrochloric acid, and mercuric chloride is obtained. 
 The fact that the mercury in the compound is in the 
 mercurous condition, and that the substance readily 
 unites with water in the presence of dilute acids 
 giving rise to acetaldehyde, seems to point to the 
 fact that it may be a substituted aldehyde of the 
 formula, CH(HgF) 2 CHO. It may also be a sub- 
 stituted vinyl alcohol which also would give rise to 
 acetaldehyde when decomposed. The production of 
 iodoform also indicates this. The mode of formation 
 of the compound may be represented as follows : 
 
 C 2 H 2 +2HgF 2 =C 2 (HgF) 2 + 2 HF, or , 
 
 C 2 (HgF) 2 +HOH = CH(HgF):C(HgF)OHor, 
 
 CH(HgF) 2 CHO. 
 
 The formation of acetaldehyde from the compound 
 is represented thus . 
 
 CH(HgF):C(HgF)OH+2HF=(CH 2 :CHOH)+ 
 
 2HgF 2 , 
 (CH 2 : CHOH) =CH 3 CHO. 
 
I 4 6 - 
 
 There is more evidence in favor of the vinyl 
 alcohol formula for the compound. If the mercury 
 derivative had an aldehyde formula it would probably 
 be likely that it could be formed from acetaldehyde 
 and mercuric fluoride solution. Acetaldehyde does 
 not react with mercuric fluoride with the formation 
 of a precipitate. 
 
 It is most likely then a vinyl derivative that gives 
 off acetaldehyde when decomposed. It is analogous 
 to the vinyl mercury derivatives prepared by Polleck 
 and Thiimmel. 
 
 Keiser's compound, C 2 (HgCl) 2 +H 2 O is none other 
 than the product, CH(HgCl): C(HgCl)OH prepared 
 by Polleck and Thiimmel from ether derivatives. 
 
 In conclusion I wish to thank Mr. W. Waggaman 
 for his kind assistance in supplying me with the 
 electrodes of calcium carbide used in the electrolytical 
 experiments. I thank him also for assisting me to 
 set up the apparatus, etc. 
 
 Notre Dame, Indiana, 
 October, 1904. 
 
147 
 
 BIOGRAPHICAL. 
 
 Julius A. Nieuwland was born near Ghent, 
 Belgium, February 14, 1878. In 1880, his parents 
 came to the United States, and settled in South 
 Bend, Ind. His first instruction was received in 
 St. Mary's parochial school in that place. In Sep- 
 tember, 1892, he entered the preparatory courses at 
 Notre Dame University, and was graduated with the 
 degree of Bachelor of Arts in 1899. After a novitiate 
 in the Congregation of Holy Cross, at Notre Dame, 
 Ind., he entered Holy Cross College, Washington, 
 D. C. , where he pursued his theological studies. He 
 was -ordained to the priesthood December 19, 1903. 
 Having entered the Catholic University of America 
 in 1900 as a graduate student in the Faculty of 
 Philosophy he followed the course of chemistry as a 
 major subject, and botany, experimental psychology 
 and biology as subordinate studies. 
 
148 
 
 INDEX. 
 
 PART I. 
 
 HYDROGENATION OE ACETYLENE I 
 
 History of the Synthesis of Ethylene I 
 
 1. Action of Sulphuric Acid on Acetylene 9 
 
 History of the Reaction of Sulphuric Acid on 
 
 Acetylene 9 
 
 Acetylene and Strong Sulphuric Acid 13 
 
 Acetylene and Dilute Sulphuric Acid 15 
 
 Formation of Acetaldehyde and Thioaldehyde. 
 
 Acetylene and Nitrosulphonic Acid 16 
 
 Acetylene and Chlorsulphonic Acid 16 
 
 , Acetylene and Sulphur Trioxide 17 
 
 History of Reaction of Sulphur Trioxide with 
 
 Ethylene 17 
 
 Formation of Acetylene Carbyl Sulphate 18-21 
 
 Analogy of the Reactions of Acetylene and Ethylene 
 
 toward Derivatives of Sulphuric Acid 21 
 
 Synthesis of Aldehyde from Water and Acetylene 
 
 in the Presence of Dilute Nitric Abid 28 
 
 Resume of Results 30 
 
 II. Action of Sulphuric Acid on Calcium Carbide 31 
 
 Calcium Carbide and Strong Sulphuric acid 31 
 
 First Method of Experiment. 
 Second Method of Experiment. 
 
 Calcium Carbide and Dilute Sulphuric Acid 33 
 
 Formation of Thioaldehyde. 
 Calcium Carbide and Stronger Sulphuric Acid 
 
 without Heating (Acid sp. gr. 1.82 to 1.84) 34 
 
 Formation of Crotonaldehyde. 
 
 Calcium Carbide and Monohydrated Sulphuric Acid, 36 
 II. Electrolysis of Various Solutions with Calcium 
 
 Carbide Electrodes 37 
 
 Methods of Analysis 37 
 
- 149 - 
 
 Electrolysis of Sulphuric Acid with Calcium 
 
 Carbide Electrodes 40 
 
 Electrolysis of Strong Sulphuric Acid. (Pre- 
 liminary Experiment) 40 
 
 Electrolysis of Dilute Sulphuric Acid 48 
 
 First Series of Experiments 48 
 
 Second Series of Experiments 50 
 
 Third Series of Experiments 53 
 
 Electrolysis with Slight Pressure. 
 
 Electrolysis of Calcium Hydroxide Solution 56 
 
 Electrolysis of Calcium Chloride Solution 57 
 
 At Ordinary Temperature 59 
 
 At Higher Temperature 61 
 
 Electrolysis of Zinc Chloride Solution 63 
 
 Electrolysis of Calcium Nitrate Solution 64 
 
 Under Ordinary Conditions 64 
 
 Under Increased Pressure 65 
 
 At Higher Temperatures 70 
 
 Electrolysis of Nitrates at Temperatures above 
 
 100 C 70 
 
 Electrolysis of Calcium Nitrate 70 
 
 Electrolysis of Zinc Nitrate 71 
 
 Electrolysis of Mercuric Nitrate 74 
 
 General Conclusions.. 72, 74-76 
 
 PART II. 
 
 CHIvORINATlON OF ACETYLENE 77 
 
 History of Reaction of Chlorine and Acetylene 77 
 
 1ST DIVISION. 
 
 I. Direct Action of Chlorine Gas on Acetylene Gas 84 
 
 i. Acetylene and Chlorine Hydrate 85 
 
 2. Action of a Solution of Acetylene in Acetone 
 towards a Solution of Chlorine in Carbon 
 
 Tetrachloride 86 
 
 3. Direct Union of Chlorine and Acetylene atl/ow 
 
 Temperatures 87 
 
 4. Chlorine and Acetylene at 100 C 91 
 
- 150- 
 
 5- Chlorine and Acetylene at Temperatures 
 above 100 C 92 
 
 2ND DIVISION. 
 
 II. Action of Acetylene towards Chlorides and Chlorin- 
 ating Agents 95 
 
 A. Reaction of Sulphuryl Chloride with Unsaturated 
 
 Hydrocarbons 95 
 
 History of the Reactions of Sulphuryl Chloride 95 
 
 The "Dissociation Theory" of Ruff 97 
 
 i. Chlorination of Acetylene with Sulphuryl 
 
 Chloride in Presence of Aluminium Chloride 100 
 
 Formation of Tetrachlorethane 101, 102, 108 
 
 Formation of Sulphone Chlorides 105, 106-108 
 
 Formation of Hexachlorethane 106 
 
 Formation of Tetrachlorethylene. 
 
 Discussion on the Action of Sulphuryl Chloride in 
 
 Presence of Aluminium Chloride 109 
 
 Reversibility of the Reaction in 
 
 Conclusions 112 
 
 2. Chlorination of Ethylene with Sulphuryl 
 
 Chloride in the Presence of Aluminium Chloride, 1 13 
 
 Formation of Ethylene Chloride 113, 115 
 
 Formation of Tetrachlorethane 114 
 
 Formation of Chlorisethionyl Chloride 115, 116 
 
 3. Chlorination of Amylene with Sulphuryl Chloride. 
 Formation of Dichlorpentane and Trichlorpentane. 
 
 A. Reaction of other Chlorides with Acetylene 117 
 
 i. Acetylene and Disulphur Dichloride (S 2 C1 2 ) 117 
 
 Formation of Tetrachlorethane and Derivatives. 
 
 2. Acetylene and Sulphur Dichloride (SC1 2 ) 120 
 
 3. Thionyl Chloride, (SOC1 2 ) and Acetylene 121 
 
 4. Stannic Chloride, (SnCl 4 ) and Acetylene 121 
 
 5. Plumbic Chloride, (PbCl 4 ), Plumbic Ammonium 
 
 Chloride (PbCl 4 2NH 4 Cl), and Acetylene 122 
 
 6. Carbonyl Chloride, (COC1 2 ) Cyanogen Chloride 
 
 (CnCl) and Nitrosyl Chloride (NOC1) 122 
 
 7. Antimony Trichloride (SbCl 3 ) and Phosphorus 
 Pentachloride (PC1 5 ) 122 
 
8. Chromyl Chloride CrO 2 Cl 2 ) 123 
 
 9. Arsenic Trichloride (AsCl 3 ) 123 
 
 io. Acetylene and Dry Iodine Trichloride(ICl 3 )....i24 
 
 Formation of Tetrachlorethane. 
 II. Acetylene and "Aqua Regia" 126 
 
 Formation of Tetrachlorethane, Hexachlorethane 
 
 and Nitro-derivatives. 
 12. Acetylene and Antimony Pentachloride 128 
 
 Laboratory Method of Preparing Tetrachorethane, 136 
 
 APPENDIX. 
 
 REACTION OF ACETYLENE TOWARDS ACIDIFIED MERCURIC 
 
 FLUORIDE 138 
 
 OF THE 
 
 UNIVERSITY 
 
 OF 
 
152 
 
 ERRATA. 
 
 On page 17, line 19, read "water" for "the anhydride.' 
 
 On page 67, line 16, put "(C)" for "(G)." 
 
 On page 67, line 27, for "tighty " read "tightly." 
 
 On page 83, line i, for "derivities" read "derivatives." 
 
 On page 95, line 3, in title, put "reaction" for "reation. 
 
 On page 100, line 15, read "retarded ' for " retailed." 
 
 On page 113, line i, insert "to" after "due," to read ' 
 
 was probably due to," etc. 
 On page 121, line 9, read "ordinary " for "oridinary." 
 
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