30 VI.-Noteon the Bwiling Points of Isomeric Ethers of the Formula CnH,nO,. By J. ALFREDWANKLI-N. FROMKopp's paper it would seem that those ethers of the fatty acids which are isomeric with one another should have the same boiling point or that all the ethers having the formula C,H,,O, in which n has a constant value have the same boiling point This proposition and its consequences have found a place in the Handbook s.* Having had occasion to prepare valerianxte of ethyl and acetate of amyl both of which have the same total formula viz. I have observed that thcre is a coiisiderable difference in their boiling points. Valerianate of ethyl boils at 133"C. ;acetate of amyl at 140"C. The boiling point of acetate of amyl was found hy Cahours to be 125"C.but it is probable that there was arnylic alcohol present iu the specimen examined by that chemist. A mixture of acetate of amyl with a good deal of amylic alcohol and a little moisture would not be distinguishable from pure acetate of amyl by a combustion. The acetate of amyl which was employed for the determination just given was prepared so as to be free from arnylic alcohol. That it was tolerably pure was ascertained by an alkalimetrical analysis. The natural conclusion from this and a number of facts of a like kind is that Kopp's laws respecting boiling points are not much to be depended on. From the glycols we have learnt that it is not universally true tliat homologous bodies rise in boiling point as they increase in complexity and a careful examination of almost every homologous series discloses the fact that "the iucre- ment "is not uniform in all parts of the same series.Thus for instance iodide of riietliyl boils at 43OC. iodide of ethyl at 73",and iodide of amyl at 146"C. giving an increment of 30' for the first additiou of CH, and an increment of J2-O or 24.3' for each CH between ethyl and amyl. * See Kekuls's ''Lehrbuch der Organischen Cliemie," dritts Lieferung page 601 ;also Limprich t's bmk page 256 et seq. BASSETT ON THE ACTION OF CHLOROPICRIN ETC. Again zinc-methyl boils at 46"C. zinc-ethyl at 119"C. differ-ence 73"for CH,; whilst zinc-amyl boils at 22OOC. difference for CH equals 1%' or 33.7". There is also the well known example of methylic alcohol which boils at 65O C. instead of at 59"C. or 60°C. as Kopp's theory would require. Higher up in the alcoholic series we encounter Wur tz's isomeric amylic alcohols having different boiling points and then the isomeric hexylic alcohols. Although it will be ob-jected that the hydrate of amylene and the P-hexylic alcohol are not true homologues of ethylic alcohol still the unexpected boiling points of these bodies shows that mere inspection of the molecular formula of an alcohol is very little guide to the boiling point of that alcohol.