Chemical Constitution of Saline Solutions. 263 
Composition of a second Hydrate. 
Some of the hydrated crystalline salt was placed in a watch-glass over sulphu- 
ric acid under a bell-jar, and weighed at intervals during a fortnight until the 
weights became practically constant. The temperature varied from about 11° C. to 
16° C. during this period. The colour of this salt is yellow. 
Ie Tl, 
Weight of salttaken,. . . . . . 271845 5°5618 
LOSS OF WORMS 1), 5 5 6 5 5 OBI 1:2398 
H,0 lost, per cent. OS ce Bi ema PETS} 22:29 
We arrive then at the following figures as expressing the hydration of the salt 
dried at the normal temperature when kept in a dry atmosphere. 
I. II. 
Per cent. Per cent. 
Water lost by crystals at 100° C., . . . . . . 38°47 32°21 
Water lost over sulphuric acid, Tsetse sy Igy 322208 22:29 
Combined waterin hydrate, . .. .... . 10:89 10:92 
This is one-third that in the original salt which, as will be seen below, is six 
molecules. 
Composition of the two Hydrates. 
Found. Calculated for NiBr2°6H.0. 
L INL. 
NIMES get tet a 88S 1792 17:96 per cent. 
Brageerean ty ey Aru iges. 48°61 ARNT oo 
H,0 at 20°C., . . . 33:47 33:21 BOT oy a 
99°74 100-00 
Composition deduced from the Analysis. | Calculated for NiBr2°3H,0. 
Ni, 5 0 0 0 0 0 PBS (GP Ctl | 23°17 per cent. 
TED, < Ge ee nner Graremare | BMT op 
HeOwmee ag 407... 9,5 | INL ..  « 
100:00 | 100-00 
Nickel Lodide and its Hydrates. 
As in the previous case, nickel clippings to the amount of 59 grs. were placed 
in a platinum dish and covered with iodine and water. As the action was slow 
some hydriodic acid was prepared specially for the purpose and added to the 
contents of the dish. As soon as hydrogen was evolved, more iodine was added 
until all the metal had entered into solution. Excess of iodine was removed by 
boiling. 
The solution while hot and concentrated was of a rich brown colour, but on 
cooling it became moss-green. The hydrated salt crystallized out in handsome 
202 
