504 
DR. PLAYFAIR ON THE NITROFRUSSIDES, 
on the same specimen, but crystallized over again for analysis II. No. III. is on a 
totally different specimen. 
I. 14'40 grs. gave 8*62 grs. sulphate of barytes and 3' 12 grs. oxide of iron. 
II. 15‘90 grs. gave 1017 gi's. sulphate of barytes and 3‘68 grs. oxide of iron. 
III. 14‘135 grs. gave 8‘47 grs. sulphate of barytes and 3 06 grs. oxide of iron. 
The combustions were made with chromate of lead. 
I. 11735 grs. gave 7*730 grs. carbonic acid and T390 gr. water. 
11. lO'GlO grs. gave 7'145 grs. carbonic acid and 07OO gr. water. 
III. 14'045 grs. gave 8’800 grs. carbonic acid and r900 gr. water. 
Iron . , 
Barium , 
Carbon 
Hydrogen 
I. 
II. 
III. 
t Crystallization. 
2nd Crystallization, 
New portion. 
. 15-16 
16-27 
14-76 
. 35-57 
37*59 
37*85 
. 17*96 
18-34 
17*08 
1-31 
0-73 
1-50 
But a new portion of barytes salt did not give the same result; the portion ana- 
lysed was in prismatic crystals, and crystallized twice. 
I. 1 1-65 grs. gave 6-58 grs. sulphate of barytes and 2*49 grs. oxide of iron. 
II. 17'22 grs. gave 9‘83 grs. sulphate of barytes and 3*58 grs. oxide of iron. 
I. 6'87 grs. gave 3-87 grs. carbonic acid and 0‘52 gr. water. 
II. 13-62 grs. gave 7'44 grs. carbonic acid and 0-69 gr. water. 
Iron 
Barium 
Carbon 
Hydrogen . 
IV. 
V. 
1st Crystallization. 
2nd Crystallization. 
. . 14-96 
14-55 
. . 33-23 
33-60 
. . 15-41 
16-38 
. . 0-83 
0-55 
Another portion, in flat prismatic crystals, made by neutralizing nitroprussic acid 
with carbonate of barytes, gave the following results : — 
12-33 grs. gave 6-61 grs. sulphate of barytes and 2-42 grs. peroxide of iron. 
6-60 grs. gave 4-005 grs. carbonic acid and T040gr. water. 
VI. 
Iron 13-73 
Barium 31-53 
Carbon 16-52 
Hydrogen 1 -75 
In this case the salt lost no more in the water-bath, although this was to have been 
expected from its larger quantity of hydrogen. 
In all these cases the specimens were excellently crystallized, and yet there is a 
