A NEW CLASS OF SALTS. 
497 
soluble niti’oprusside. Before however being completely decomposed, a dark-coloured 
basic nitroprusside of iron is produced. 
A salt dried in the hot chamber, at a temperature about 90° Fahr., still lost water 
when exposed in the water-bath : — 
14‘162 grs. lost at 212° 2‘890 grs., or 20‘406 per cent. 
10’893 grs. lost at 212° 2'320 grs., or 21-298 per cent. 
17-500 grs. lost at 212° 3-545 grs., or 20-257 per cent. 
In the two first analyses given below, the iron was determined by decomposing the 
salt by sulphuric acid, oxidizing with nitric acid and precipitation by ammonia. The 
third estimation was by calcination, a little nitrate of ammonia being used to effect 
complete oxidation. 
I. 1 8-075 grs. gave 9-917 grs. peroxide of iron. 
II. 30-935 grs. gave 16-900 grs. peroxide of iron. 
III. 9-220 grs. gave 4-995 grs. peroxide of iron. 
The combustions were performed with chromate of lead. 
I. 7-2I8 grs. gave 0-717 gi’- water and 5-255 grs. carbonic acid. 
II. 7*347 grs. gave 0-810 gr. water and 5-360 grs. carbonic acid. 
III. 6-360 grs. gave 0-693 gr. water and 4-695 grs. carbonic acid. 
The nitrogen was determined by Dumas’ quantitative method. 
5-427 grs. gave 86 CC. nitrogen gas, the thermometer being 48°-7 Fahr. (9-4 Cent.) 
and the barometer 29-285 inches. 
Iron . . . 
I. 
. 38-406 
II. 
38-241 
III. 
37-922 
Mean. 
38-189 
10 
280 
Calculated 
38-35 
Carbon . . 
. 19-855 
19-896 
20-136 
19-962 
24 
144 
19-72 
Nitrogen . 
. 29-285 
29-285 
29-285 
29-285 
15 
210 
28-76 
Hydrogen 
1-103 
1-224 
1-210 
1-179 
8 
8 
1-09 
Oxygen . 
. 11-351 
11-354 
11-447 
11-385 
11 
88 
12-08 
100-000 
100-000 
100-000 
100-000 
730 
100-00 
The formula of the iron salt, dried at 212°, would therefore be 
Feg Cy^2 3NO Fe 5 + 8 HO. 
Nitroprusside of Zinc. 
17. This salt is prepared by precipitating one of the soluble salts of zinc by a nitro- 
prusside. It is a salmon-coloured precipitate, of a more fleshy colour than the iron salt. 
When formed slowly, as when muriatic acid and zinc are made to act on nitroprusside 
of soda, it is of a deep orange colour. 
Nitroprusside of zinc is very slightly soluble in cold water, rather more so in hot 
water. In its behaviour to reagents it acts exactly like the iron nitroprusside. It 
was analysed by decomposing it with sulphuric acid, separating the iron by succinate 
of ammonia and determining the zinc as a carbonate. 
