1865.] On the Acids of the Lactic Series. 17 



II. "Notes of Researches on the Acids of the Lactic Series. 

 No. II. Action of Zinc upon a Mixture of Iodide of Ethyl and 

 Oxalate of Methyl." By EDWARD FRANKLAND, F.R.S., and 

 B. F. DUPPA, Esq. Received December 20, 1864. 



In our former communication * on the action of zinc upon a mixture of 

 iodide and oxalate of methyl, we described a process by which the use of 

 the zinc-compounds of the alcohol radicals may be dispensed with in the 

 production of the series of acids which we are now investigating. We 

 then described this process as being conducted at a temperature of 70 to 

 1 00 Cent, for twenty-four hours, until the mixture had solidified to a yellow- 

 ish gum-like mass, which on distillation yielded a mixture of water, alcohol, 

 and the ether of the new acid. Subsequently we have found it more ad- 

 vantageous to continue the operation for a much longer time at a lower 

 temperature, thereby obtaining a crystalline instead of a gum-like pro- 

 duct, the former giving a much better result as regards the production 

 of ether. 



In the reaction which forms the subject of the present Note, we have 

 proceeded in the following manner. Two atoms of iodide of ethyl were 

 mixed with one of oxalate of methyl and placed in a capacious flask, with 

 zinc in sufficient quantity to be barely covered by the ethereal mixture. 

 We prefer to use zinc which has been employed in a previous operation, 

 as we find it to act not only with greater rapidity, but also at a much 

 lower temperature. The time required for the completion of an operation 

 is about ninety-six hours at a temperature of from 30 to 50 Cent. 

 During the first eighteen or twenty hours no apparent action takes place, 

 the liquid remaining perfectly limpid, and the zinc apparently untouched ; 

 but after this period a straw-coloured tint gradually makes its appearance 

 and slowly increases in intensity, until the liquid solidifies to a mass of 

 crystals which scarcely fuse at 50 Cent. The operation may now be con- 

 sidered as ended, although a considerable quantity of the mixed ethers is 

 still unacted upon. Water being now added by slow degrees until it 

 equals three times the volume of the crystalline mass, a copious effer- 

 vescence takes place ; oxalate and oxide of zinc are formed in abund- 

 ance, whilst, on the application of heat, alcohol, accompanied by a con- 

 siderable quantity of an ethereal body, distils over along with the iodide 

 of ethyl that has not been acted upon. The addition of water to the 

 distillate effects an approximate separation of the ethereal from the alco- 

 holic portion ; the former is then decanted and distilled for the purpose 

 of separating alcohol and iodide of ethyl. When the temperature of 

 ebullition rises to 100 Cent., the liquid left in the retort is placed over 

 chloride of calcium for twelve hours, after which it is again submitted to 

 distillation, when its boiling-point almost immediately rises to 165 Cent. 



* Proc. Roy. Soc. vol. xiii. p. 140. 



