569 



stant boiling-point on redistillation. Submitted to analysis, it yielded 

 results agreeing with the formula 



This body, for which we propose the name boric ethide, is pro- 

 duced by the following reaction : 



{C 4 H 3 O 3 fr TT fQlH- r F 



C 4 H 5 2 + 3Zn 2 {H 5=2B J C 4 H 5 + 6 C * 

 C 4 H S 2 L ^ U5 \.C 4 H 5 



Boracic ether. Zincethyl. Boric ethide. Ethylate of zinc. 



The ethylate of zinc thus formed combines with zincethyl to form 

 the crystalline compound above alluded to. 



Boric ethide possesses the following properties : It is a colourless 

 mobile liquid of a pungent odour ; its vapour is very irritating to the 

 mucous membrane, and provokes a copious flow of tears. The spe- 

 cific gravity of boric ethide at 23 C. is -6961 ; it boils at 95 C., 

 and the results of several determinations of its vapour-density give 

 the number 3*4006. The calculated vapour-density of boric ethide, 

 volumetrically composed like terchloride of boron, is 3*3824. 



Boric ethide is insoluble in water, and is very slowly decomposed 

 by prolonged contact with it. Iodine has scarcely any action upon 

 it, even at 100 C. It floats upon concentrated nitric acid for several 

 minutes without change ; but suddenly a violent oxidation takes place, 

 and crystals of boracic acid separate. When boric ethide vapour 

 comes in contact with the air it produces slight bluish-white fumes, 

 which have a high temperature. The liquid is spontaneously in- 

 flammable in air, burning with a beautiful green and somewhat fuli- 

 ginous flame. In contact with pure oxygen it explodes. Placed in 

 a flask and allowed to oxidize gradually, first in dry air and finally in 

 dry oxygen, it forms a colourless liquid, which boils at a higher tem- 

 perature than boric ethide, but cannot be distilled under atmospheric 

 pressure without partial decomposition. In a stream of dry carbonic 

 acid this product of oxidation evaporates without residue. By distil- 

 lation in vacuo it is obtained pure, and it then exhibits a composition 



expressed by the formula 



fC 4 H s 

 B< C.H.O, 

 LC.H.O, 



