178 



CHEMISTRY. 



properties, may be actually produced chemical- 

 ly, by any of the so-called modes of synthesis. 



Acetylene. M. Berthelot has found that when 

 graphite is intensely heated by means of the 

 galvanic current in an atmosphere of hydrogen, 

 acetylene is formed in considerable quantity. 

 The same result is obtained with gas-carbon 

 and with purified wood-charcoal, though in 

 this last case with much greater difficulty, per- 

 haps because of its not being easy to heat the 

 very porous mass to the requisite high tempera- 

 ture. Under the circumstances in which ace- 

 tylene is thus formed, carbon does not com- 

 bine with chlorine, bromine, or iodine ; nor can 

 pure carbon be made to combine with pure 

 nitrogen. The spark of RuhmkoriFs apparatus 

 gives no acetylene with pure carbon and hy- 

 drogen. 



Alcohol from, Olefiant Gas. M. Berthelot 

 considers that his experiments have sufficed to 

 prove that the alcohol produced by his method 

 from olefiant gas (C 4 H 4 ), and common alcohol 

 derived from the vinous fermentation, are not 

 merely analogous and yet distinct bodies, but 

 that they are in every respect identical there 

 being no physical or chemical distinction be- 

 tween either these alcohols or their ethers. 

 Thus, the ethyl-sulphate of barytes obtained 

 from ordinary alcohol is the same as that from 

 the olefiant alcohol ; and when the latter is 

 treated with chromic acid, it gives rise to an 

 ether and to acetic acid which are in no way 

 distinguishable from those produced in similar 

 manner from ordinary alcohol. 



Manufacture of Alcohol by means of Olefiant 

 Oas. M. J. Nickles gives an interesting state- 

 ment upon this subject (" American Journal of 

 Science," Nov., 1863) which we condense : 



The industrial world has been, tor some 

 time, much interested in a process for pro- 

 ducing alcohol by means of illuminating gas, 

 at a very low cost 25 francs (18f cts. each) 

 per hectolitre (about 22 gallons), or about 21 

 cts. per gallon. It has been stated in some 

 journals that the manufacture is going on at 

 St. Quentin ; and that the apparatus, taking in 

 coal upon one side, pours out alcohol on the 

 other 1 These statements are exaggerations; 

 but a company at St. Quentin are now actually 

 engaged in attempts at such a manufacture, 

 under a patent of Mr. Ootelle, founded on 

 Berthelot's synthesis of alcohol (1855) in the 

 way of causing sulphuric acid to absorb olefiant 

 gas (C<H), with the production of sulpho-vinio 

 acid, which is then readily turned into alcohol 

 (C 4 H.O,). 



Cotelle employs chiefly illuminating gas, 

 which contains from 4 to 12 per cent, of C 4 H. 

 He purifies the gas from sulphydrio acid and 

 ammonia ; and he then desiccates it by passing 

 it over mono-hydrated sulphuric acid. The dry 

 gas is then drawn along by suction and direct- 

 ed to a column of glass or sandstone furnished 

 with trays or diaphragms pierced with small 

 holes, from which descends the same acid and 

 of the same strength as just named, to meet and 



dissolve the C 4 H 4 . This solution, which takes 

 place slowly, may require a succession of 40 

 such trays, to take up all the olefiant gas and 

 secure saturation of the acid. The sulpho-vinic 

 acid thus obtained is next treated with 5 times 

 its volume of water ; a stream of vapor is made 

 to carry over the alcoholic product ; the va- 

 pors are condensed ; the alcoholic liquid ob- 

 tained is redistilled over a little lime, to re- 

 move any traces of sulphuric acid, and the 

 liquid condensed from this distillation is recti- 

 fied to produce alcohol of 90. 



The residue of the illuminating gas, consist- 

 ing largely of C 3 H 4 , CO, H, &c., can be advan- 

 tageously used^for fuel, thus offsetting in part 

 the cost of making the gas in the outset, and 

 rendering the expense of it small, especially if, 

 as near the mines, use can be made of the gas 

 which issues from the coke furnaces. To pro- 

 duce one hectolitre of alcohol of 90 per cent., 

 about 40 cubic metres of C 4 H<, answering to 

 about 2 tons of the coal employed, are required. 

 Among the chief practical difficulties, thus far, 

 are the large amount of the acid requisite (10 

 parts to 1 of the alcohol product), and its great 

 deterioration; in the latter respect, the acid, 

 employed at a strength of 66 of Beaume'e are- 

 ometer, being after the process reclaimed at 

 from 20 to 25 ; so that while a hectolitre of 

 alcohol requires for its production 1500 kilo- 

 metres (?) of sulphuric acid at 66 B., the acid 

 after use must either be turned to some ac- 

 count in its dilute state, or must be concen- 

 trated for a new process; and hence, to all the 

 other apparatus there must be added that for 

 concentration, or leaden chambers. It is de- 

 clared, however, that these difficulties are 

 be ing gradually overcome. 



Bases of Anilin Colors. Prof. A. TV. Hof- 

 mann has continued his researches into the 

 composition and properties of the derivatives 

 of anilin. He finds that the oxidation of anilin 

 results in a beautiful yellow coloring matter, 

 which he terms chrysanilin. This base accom- 

 panies rosanilin in all the usual modes of pre- 

 paration. Isolated, it is a fine yellow amor- 

 phous powder, very soluble in alcohol and 

 ether. It yields two classes of well crystallized 

 salts, being monacid and biacid : its nitrate is 

 so insoluble as to constitute chrysanilin the best 

 known reagent for nitric acid. By the action 

 of the .chlorides of carbon, tin, mercury, and 

 other metals, and of certain oxidizing agents 

 upon anilin, the red coloring matter is pro- 

 duced: this organic base he terms rosanilin. 

 Pure, it is colorless, crystalline, and slightly 

 soluble in water, and becomes red on expo- 

 sure to the air. It dissolves in alcohol with a 

 dark red color. The change in color is not 

 attended with change of weight. This base 

 forms three classes of salts, monacid, biacid, 

 and triacid. The dry salts of the first of these 

 classes show a greenish lustre, but by transmit- 

 ted light are red ; their solutions are of a mag- 

 nificent red color. Rosanilin, by action of 

 nascent hydrogen, is converted into another 



