CHEMISTRY. 445 



raal origin is now fiirnisbed by the researches of 0. Engler, who studied 

 the distilhitiou of tish oil under favorable conditions. In a large appa- 

 ratus made for manufacturing purposes he distilled 492 kilogrammes of 

 menhaden oil, at a temperature of 350° to 400°, and under a pressure 

 of two atmospheres. Combustible gases were given off, and a liquid 

 distillate was obtained in two layers ; the upper watery, the lower oily, 

 in character. The latter amounted to 299 kilogrammes, was brownish, 

 and had a strong green Huorescence. In brief, it resemble<l crude 

 petroleum ; and on fractional distillation it yielded pentane, hexane, 

 heptane, octane, and nonaue, all of the normal series, together with 

 some secondary hydrocarbons. It was essentially an artificial petro- 

 leum. 



As fish oil is mainly a mixture of triolein, tristeariu, etc., Engler made 

 further experiments upon a similar distillation of these compounds, 

 although on a very much smaller scale, and obtained confirmatory re- 

 sults. The fact that petroleum contains no free carbon, which is cited 

 as evidence against its organic origin, he disposes of by showing that 

 if all the oxygen in the glycerides of fatty oils should combine with 

 part of their hydrogen to form water, the residue would still contain 87 

 per cent, carbon and l.'i per cent, hydrogen, whicli is almost exactly the 

 average composition of natural petroleum. (Berichte, xxi, 1816.) 



Mctallocyanides of ethyl. — The ferrocyauide, (C2Hr,)4 FeCye, is de- 

 scribed by Freuud, who prepared it by acting upon silver ferrocyauide 

 with ethyl iodide. Recrystallized from chloroform it forms large rhom- 

 bic crystals. Freund also makes some observations on von Tban's 

 alleged platinocyauide of ethyl. (Berichte, xxi, 931 and 937.) 



O.rymethykne and formaldehyde. — Tolleus and Mayer, attempting to de- 

 termine the molecular weight of osjtnethylene by Kaoult's method, find 

 that upon solution in water it is converted into formaldehyde. The 

 latter, m dilute solution, did not undergo polymerization, even after six 

 months' standing, nor was it expelled upon heating; this fact being ex- 

 plained by its transformation, in concentrated solution, into a polymer 

 (CU^O).. Upon standing, this di- or paraformaldehyde quickly disso- 

 ciates at ordinary tem])erature into formaldehyde. The oxymethylene, 

 which is with difficulty soluble, is probably metaformaldehyde (CH20)3. 

 (Berichte, xxi, 1560 and 3r)03.) 



Diacetyl. — By acting upon nitrosomethyiacetoue with a solution of 

 sodium bisulphite, H. v. Pechmanu has prepared a compound which 

 appears to be diacetyl, CH3.CO.CJ.CH3. It is a volatile liquid boil- 

 ing at 87° to 88°, having a yellowish-green color, and an odor like crude 

 acetone. Its vapor resembles chlorine in tint. Homologues of uitro- 

 somethylacetone, similarly treated, yield homologues of diacetyl. (Be- 

 richte, XX, 3162.) 



In a later pa{)er I'eclimann and Otte describe acetyl-butyryl, acetyl- 

 isobutyr.vl, acetyl-isovaleryl, acetyl-isocaproyl, and acetyl-croton^l. 

 (Berichte, xxi, 2140.) 



