too Mr. W. Brande's Chemical Researches on the Blood , 
by the action of electricity, was copiously precipitated by in- 
fusion of galls. 
It may be inferred from these experiments, that gelatine 
does not exist in the serum of the blood, and that the serosity 
Consists of albumen in combination with a large proportion of 
alkali, which modifies the action of the re-agents commonly 
employed, but which is readily separated by electrical decom- 
position. 
To ascertain whether iron exists in the serum of the blood,, 
one pint was evaporated to dryness in a crucible, and gradu- 
ally reduced to a coal, which was incinerated and digested in 
muriatic acid, to which a few drops of nitric acid were added? 
some particles of charcoal remained undissolved ; the solution 
was saturated with ammonia, which afforded a copious preci- 
pitation of phosphate of lime, accompanied with slight traces 
only of oxide of iron. 
SECTION V. 
Some Experiments upon the Coagulum of Blood. 
Mr. Hatchett's valuable researches on the chemical con- 
stitution of the varieties of coagulated albumen, have shewn 
that that substance varies but little in its properties, whether 
obtained from the crassamentum of the blood, or from washed 
muscular fibre, or other sources ; but that the proportion of 
earthy and saline matter is different in the different varieties.* 
It will also be remarked, on referring to the dissertation 
which I have just quoted, that the ashes obtained by incinerat- 
• Phil. Trans. 1800, p. 384. 
