Chemistry and Physics. : 305 
dissolved in caustic payee water, the washed barium bromat 
converted into bromide b ——s — this distilled with aides 
ric acid and potassium dichro e distillate was washed 
and dried; a part by —- with cae ated sulphuric acid 
and distillation and a part by distillation from calcium chloride. 
° 
Thus purified, the bromine solidified between —7°2° and —7:3 
with that obtained by Regnault — 7-3 The non-pu ro- 
mine solidified at —9° to —10°. To rai the psa ms foreign 
admixture, the author made direct experimen und that 
ile 2 per cent of iodine di sa materially raise the siping 
es , 3 or 4 per cent of chlorine lowered it eve 
romine has a ape dea color and a conchoidal fracture; ‘thos -h 
after exposure to the it takes a gray color recalling that of 
ape and perl pene ibieniag Berl. Chem. Ges., xii, eee 
u 
3. On tz Thermic formation of Hydrogen silicide a ey of 
Ethyl silicate—Oaiex has studied, in Berthelot’s fe pesboe the 
heat-relations attending the formation of hydrogen silicide and of 
ethyl silicate. The hydrogen silicide was prepared by the action 
of sodium on tribasic siliciformic ether, and was free from hydro- 
4 
= 24: 8 ealoriek: He ene a nitin ia d H. evolve ae ; get, 
ries, a number very near ‘that which the rsaiee of marsh gas 
gives, +22. 
The heat of formation of silicic ether was determined in two 
Ways: first, analytically, by decomposing it by means of a large 
quantity of water, into silicic acid and alcohol, at the ordinary 
method ave +-21°6 edias as the heat evolved in the decompo- 
‘Taken with the contrary sign, it expresses the hea 
id, Sn cting from this the heat corresponding to the solution 
of the alcohol in water, there is left — 1144 calories, the true heat 
26 equivalents of alcohol was 42°3 calories at 10°. Making the 
hecessary corrections, the heat of formation of silicic ether ob- 
— ~ nike way, is —11°56 calories, a close accordance with the 
ohisined analytically, 11-44. Referred to a single 
ae of alcohol instead of four, it becomes —2°9.— Bull. Soe. 
pre Il, xxxii, 116, 118, Aug., 1879, G. F. B. 
oun. Sor —Tup Sent, VoL oL. XVIII, No, 106.—Ocr., 1879. 
