GEGAi^IC COMPOUNDS CONTAINING BOEON. 
171 
Weight of boric ethide 
Observed volurae of vapour 
Temperature of oil-batb . . . . / / . 
Height of barometer ' 
Height of mercury inside of tube above that outside 
Height of column of oil 
*2839 grm. 
96’68 cub. centims. 
149° C. 
760 '5 minims. 
1'5 millim. 
328'0 millims. 
From these data the specific gravity of the vapour was calculated to be 3*4006. This 
number agrees very closely with that’ calculated upon the supposition that boric ethide 
is volumetrically composed like terchloride of boron, as is seen from the follo’wing 
calculation : — 
1 vol. Boron vapour *75319 
3 vols. Ethyl 6*0117 
The 4 vols. condensed to 2 vols. . . 2)6*76489 
3*38244 
The density of boric ethide vapour increases considerably as the temperature 
approaches the boiling-point; thus a determination made at 132° gave the number 
3*5979, whilst a second showed the specific gravity of the vapour atl01°*6 to be no less 
than 3*757. 
Boric ethide is insoluble in water, and is very slowly decomposed by prolonged con- 
tact 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 
reaction takes place, and crystals of boracic acid separate. When boric ethide vapour 
comes in contact with air, it produces slight bluish-white fumes, which in the dark are 
seen to proceed from a lambent blue flame. The liquid is spontaneously inflammable 
in air, burning with a beautiful green and somewhat fuliginous flame. In contact with 
pure oxygen it explodes. Excluded from the air, boric ethide is quite a stable body ; a 
quantity of it kept in a sealed tube for two years exhibited, on examination, no evidence 
of any alteration. 
When boric ethide is heated to 99° C. with strong hydrochloric acid over mercury, a 
considerable quantity of hydride of ethyl is slowly evolved; *0517 grm. of boric ethide, 
thus treated as long as gas was evolved, gave 35*33 cubic centimetres at 11°*1 C. and 
248*4 millimetres mercurial pressure, corresponding to 11*11 cub. centims. at 0°C. and 
760 millims. pressure. The reaction 
[^4^5 rC4H5 n XT *1 
iC4H, [ Cl 
requires that 11*31 cub. centims. of hydride of ethyl at 0° C. and 760 millims. pressure 
should be liberated. That the gas thus evolved is hydride of ethyl is established by the 
following data : — 
z 2 
