SYNTHETICAL EESEAECHES ON ETHEES, 63 



are only apparently isomeric. If reduced to the tetratomic carbon type, they both 

 become CMeEtO. This is the formula of methylated acetone, described above, of 

 niethylacetone obtained by Fittig* in distilling lead acetate, and of ethyl-acetyl obtained 

 by FKEUNof in acting upon acetyl chloride with zinc-ethyl. Unless physical causes 

 of isomerism be assumed, there can be little doubt as to the identity of these three 

 substances, the only difference known being in their boiling-points, which are as follow : — 



Barometer. 



Methylated acetone ..... 81° C. about 760 millims. 



Ethyl-acetyl 77°-5-78°C. about 738 millims. 



Methyl acetone 75°-77'C. 



The discrepancy betAveen the first two ceases to be remarkable when the difference of 

 pressure at which their boiling-points were determined is taken into account, and when 

 it is remembered that our methylated acetone probably retained traces of dimethylated 

 acetone which boils at 93°-5 C. Fittig does not give the boiling-point of his methyl 

 acetone as an exact determination, remarking that " a more accurate determination of 

 the boiling-point was obliged to be abandoned on account of the small amount of liquid 

 available." 



The origin of Fittig's methylacetone does not afford any satisfactory clue to its con- 

 stitution, but the production of ethyl-acetyl and methylated acetone by synthetical pro- 

 cesses, not only confirms the commonly received view of the constitution of the ketones, 

 but also proves the identity of these two bodies. The formation of ethyl-acetyl by 

 Freund's process shows that it consists of two bodies of the composition of the radicals 

 indicated by the name, whUst the formula for methylated acetone, above given, if rightly 

 interpreted, affirms the same thing. 



fCaHs rCMeHg 



IC2H3O ICMeO 



Ethyl-acetyl. Methylated acetone. 



The presence of methyl in the so-called acetyl has been abundantly proved, conse- 

 quently the chlorous radical is the same in both the above formulae, whilst the for- 

 mation of butyric acid, by the substitution of ethyl for hydrogen in the methyl of acetic 

 acid, proves that ethylated methyl is identical with propyl, and that consequently 

 methylated methyl is the same thing as ethyl, therefore the basylous radicals in the 

 above formulae are also identical. 



Butyral, which is isomeric with methylated acetone, has been classed by KEKULfi 

 amongst the ketones, but we cannot agree with this classification, as, unlike a ketone, 

 it yields on oxidation a fatty acid containing the same number of atoms of carbon, and 

 it also reduces with facility ammoniacal solution of silver oxide ; in fact Kekul^'s own 

 definition of a ketone excludes it completely from this class of bodies. Butyral does 

 not appear to be identical with the butyraldehyde obtained by the oxidation of protein 



* Ann. der Ch. und Pharm. ex. 17. t I^^- cxviii. 1. 



e2 



