DE. A. G-AMGrEE ON THE ACTION OE NITEITES ON BLOOD. 
623 
and sulphide of ammonium are added. When a concentrated solution of hsemoglobin 
is treated with a solution of nitrite of silver and then with alcohol, and placed in a 
freezing-mixture, a precipitate separates, which is usually amorphous, and has a choco- 
late colour. Sometimes it is very readily soluble in water, holding a trace of ammonia 
in solution ; at other times it is soluble only with difficulty. 
This precipitate, when washed and ignited, leaves a residue consisting entirely of silver 
and oxide of iron. 
When solutions of hsemoglobin which have been treated with nitrite of silver are 
exposed, or set aside for some time, a precipitate separates, which is scarcely soluble in 
ammonia ; the solution obtained has, however, all the properties of ammoniacal solutions 
of the nitrite compounds of hsemoglobin. 
a. 4-279 grms. of the nitrite of silver compound yielded 0-0517 grm. of Ag Cl. 
1-042 grm. of the same sample yielded 0-0067 grm. of Fe 2 0 3 . 
b. 3-591 grms. of the nitrite of silver compound prepared on another occasion and 
from different blood, yielded 0-0177 grm. of AgCl. 
The first sample, therefore, contained in 100 parts 0-759 of silver, corresponding to 
1-083 of Ag N0 2 ; whilst the second contained almost exactly half the quantity, or *346 
of silver, corresponding to 0-494 grm. of AgN0 2 per 100 parts of the compound. 
These two analyses clearly indicate that, although nitrite of silver enters into actual 
chemical combination with hsemoglobin, the amount which is taken up varies remarkably. 
Preyer has calculated the molecular weight of hsemoglobin on the assumption that 
each molecule of this substance yields a molecule of hsematine. The molecular weight 
of hsematine being 626 (G 32 H 34 N 4 Fe 0 6 ), that of hsemoglobin would on the above 
assumption amount to 13280. 
On the assumption that one molecule of hsemoglobin has the power of combining with 
and retaining loosely one molecule of oxygen, 13280 grammes of hsemoglobin would 
combine with and retain 32 grammes of oxygen, or 1 gramme of hsemoglobin would 
have the power of retaining 1-3 cub. centim. of oxygen at 0° C. and 1 metre pressure ; 
this number agrees, as perfectly as can be expected, with direct observations made to 
determine this point. 
If one molecule of oxygenized hsemoglobin combined with one molecule of a nitrite, 
13312 grammes of oxidized hsemoglobin would combine with 154 grammes of AgN0 2 , 
and 100 parts of the compound should contain 1-14 gramme of AgN0 2 , or 0-79 of Ag. 
Comparing these numbers with those which I found, we have 
In 100 parts. Calculated. 
Silver .... 0-79 
Iron .... 0-419 
Bound. 
0-759 0-346 
0-44 
4. Action of Nitrite of Amyl on Haemoglobin. 
If, instead of the solutions of the nitrites already mentioned, we add an alcoholic solu- 
MDCCCLXVIII. 4 Q 
