238 Proceedings of Royal Society of Edinburgh, [march 19, 
1000), nearly every trace of the corrosive sublimate is thrown 
down with the albumen in the form of the albuminate of mercury. 
The precipitate is very coarse, and much paler than blood. 
On adding stannous chloride to the filtrate, there is the merest 
trace of a darker colour ; so slight is this, that at first it is scarcely 
perceptible, and there is no definite precipitate in the test tube for 
several hours. Prom this it is evident that Laplace’s statement 
that the mercury from 5 c.c. of the sublimate solution (1 to 1000) 
is precipitated by 5 c.c. of blood, is very much under-estimated, as 
we see that 5 c.c. of blood is quite sufficient to precipitate the salt 
in 50 c.c. of the mercuric solution. Along with the serum albu- 
men the hsemoglobin is also carried down, as the filtrate is almost 
clear, and contains scarcely sufficient hsemoglobin to give the two 
characteristic spectroscopic absorption bands. (When a larger 
quantity of blood, say 50 c.c., is added and the mixture filtered, a 
considerable amount of hsemoglobin in solution comes through in 
the filtrate. This hsemoglobin solution, if put into a clean bottle, 
may be kept for a considerable time, apparently unaltered. Tested 
with stannous chloride, no trace of the corrosive sublimate can 
be detected in the filtrate.) If, instead of filtering, the mixture 
be allowed to stand in the tall glass jar for twenty-four hours, there 
is found in the lower part a pale brick-red deposit, occupying five- 
sixths of the whole column, the remaining one-sixth being occupied 
by a clear supernatant fluid, in which there is not a trace of hsemo- 
globin, and scarcely a trace of the sublimate. 
If only 2^ c.c. of blood be added to 50 c.c. of the sublimate 
solution, a large proportion of the mercury is still precipitated as 
albuminate, and can be separated by filtrati'' but on the addition 
of the stannous chloride there is a precipitate sufficient to render 
the mixture dirty brown in colour. On allowing this to subside, 
however, the precipitate is certainly not more than one-sixth as 
bulky as that obtained from a similar quantity of the sublimate 
solution unmixed with blood. With 4 c.c. of blood there is a very 
slight precipitate, which becomes dark much more slowly than in 
the above cases. 
As Lister and others have pointed out, the albuminate is redis- 
solved in excess of albumen ; after adding such excess, it was 
found that mercuric salts of some form or other again passed 
