1876.] J)t. B.YrQjoildsxidi on 07^ffano-boron Compounds. 167 



ethjl, there was obtained, by distillation in an atmosphere of carbonic 

 anhydride, a liquid product, which, on rectification, yielded a considerable 

 fraction boiling between 102° and 103° C. This fraction gave, on analysis, 

 numbers for carbon, hydrogen, and boron closely corresponding to those 

 required by the above formula. Boric diethethylate is produced from 

 diboric ethopentethylate by the following reaction : — 



BEtEto^, BEtOg + SZnEt^ = 23Et^Eto + SZnEtEto. 



Boric ethopentethylate. Zincethyl. Boric diethethylate. Zincic ethethylate. 



Boric diethethylate is a colourless, transparent, mobile, and neutral 

 liquid, of ethereal odour and pungent taste. It boils at 102° C, and 

 distils unchanged. Its vapour-density, taken at 135°'5 C, is 56'5, the 

 theoretical specific gravity for a two-volume vapour of the above formula 

 being 57 (11=1). In air, boric diethethylate is spontaneously inflam- 

 mable, burning with a green and slightly luminous flame. Exposed to a 

 slow current, first of dry air and then of oxygen, it is converted into 

 boric ethodiethylate : — 



BEt^Eto -H = BEtEto,. 



Boric diethethylate. Boric ethodiethylate. 



Boric Diethohydrate. 



When boric diethethylate is shaken up with water and then allowed to 

 stand, a spontaneously inflammable ethereal liquid, similar in appearance 

 to boric ethide, rises to the surface of the water. This Hquid cannot 

 be distilled without decomposition ; but on being submitted to analysis, 

 after drying over calcic chloride, it gave numbers for carbon, hydrogen, 

 and boron closely approximatiug to those required by the formula 



BEt.Ho. 



Boric diethohydrate has an ethereal odour and a pungent taste, very 

 unlike the intense sweetness of boric ethodihydrate. It is produced by 

 the substitution of one semimolecule of hydroxyl for one of ethoxyl, 

 according to the following equation : — 



BEt,Eto 4- OH, = BEt.Ho + EtHo. 



Boric diethethylate. Water, Boric diethohydrate. Alcohol. 



Boric Ethetliylate-liydrate. 



Submitted to a slow current of dry air, boric diethohy dilate absorbs 

 oxygen; and if the vessel in w^hich the reaction is conducted be kept cool, 

 colourless crystals gradually make their appearance. These crystals are 

 soluble in the diethohydrate; but when the oxidation of the latter is 

 completed, the entire liquid solidifies at a temperature slightly below 

 8° C, but immediately liquefies again when that temperature is exceeded. 

 Submitted to analysis, the new body gave numbers for carbon, hydrogen, 

 and boron, closely agreeing with the formula 



BEtEtoHo. 



