SYNTHETICAL EESEAECHES ON ACIDS OF THE LACTIC SERIES. 315 



|C O Eto 



jCEt,(OZn"Et) J ^^CEt^Oj,^,, 2n"I, + 2EtI. 

 (COEto ^ ' (CEUO 



Ethylic zincmonethyl 1 C O Eto 



diethoxalate. -g^^^^y^ 



zincodiethoxalate. 



It was obviously impossible to collect in a state of purity the ethylic iodide thus set 

 at liberty without considerable loss ; but the quantity of the pure iodide actually obtained 

 was 12 grms. The above equation requires 14'G grms. 



On the removal of ether and ethylic iodide, the mixture of ethylic zincodiethoxalate 

 and zincic iodide forms a transparent gummy mass easily soluble in ether, carbonic di- 

 sulphide, or caoutchoucin, but totally incapable of crystallizing from any of its solutions. 

 All our attempts to separate these bodies have hitherto proved abortive ; and it is by no 

 means improbable that they are chemically combined. 



The existence of monad ovgano-zinc radicals, such as zincmonethyl, receives further 

 support from the slow action of oxygen upon zincethyl, which clearly shows that there 

 are two distinct stages in the process of oxidation. These stages have indeed already 

 been indicated by one of us in describing the reactions of this body*. When a current 

 of dry oxygen is made to pass through an ethereal solution of zincethyl, dense white 

 fames continue to fill the atmosphere of the vessel, until about one-half of the total 

 quantity of oxygen necessary for the complete oxidation of the zincethyl has been 

 taken up. Then the white fumes entirely cease, showing the absence of free zincethyl, 

 and at the same moment the liquid, which up to that time had remained perfectly 

 transparent, begins to deposit a copious white precipitate, and the latter continues to 

 increase until the remaining half of the oxygen is absorbed. If the process of oxidation 

 be arrested when the white fumes cease to be formed, the product effervesces violently 

 when mixed with water, owing to the escape of ethylic hydride ; but when the oxidation 

 is completed, the white solid mass produced consists chiefly of zincethylate, and does not 

 in the slightest degree effervesce in contact with water. The two stages of this reaction 

 depend essentially upon the successive linking of the zinc with the two atoms of ethyl 

 by means of dyad oxygen. The first stage of oxidation is expressed by the following 

 equation, 



Zn"Et2 + O = Zn"EtEto. 



Zincethyl. Zincethylo-ethylate. 



The zincethylo-ethylate thus formed is perfectly soluble in ether, and is instantly de- 

 composed by water, according to the following equation, 



Zn"EtEto+2H2 0=Zn"Ho2 + ^Ho + "^H. 



Zincethylo-ethylate. Zinc Alcohol. Ethylic 



hydrate. hydnde. 



Treated with dry oxygen, zincethylo-ethylate in ethereal solution absorbs a second 



* Philosophical Transactions, 1855, p. 268. 



