and some other Animal Fluids . 
103 
pically examined, it seems, as Lewenhoeck first observed,* 
to consist of minute globules. These are usually described as 
soluble in water, a circumstance which my own observations 
led me to doubt, and which the more accurate experiments of 
Dr. Young, an account of which, intended for publication, he 
has kindly permitted me to peruse, have completely dis- 
proved. 
3. The effect of water upon the red globules, is to dissolve 
their colouring matter, the globule itself remaining colourless, 
and, according to Dr. Young, floating upon the surface. 
This aqueous solution is of a bright red colour, and not very 
prone to putrefaction. When heated, it remains unaltered at 
temperatures below 190° or 200* Fahrenheit ; at higher tem- 
peratures it becomes turbid, and deposits a pale brown sedi- 
ment : if in this state it be poured upon a filter, the water 
passes through without colour, so that exposure to heat not 
only destroys the red tint, but renders the colouring matter 
insoluble in water. 
Alcohol and sulphuric ether added to this solution also 
render it turbid, and when these mixtures were filtrated, a 
colourless and transparent liquor was obtained. 
4. The matter remaining upon the filter was insoluble in 
water, in alcohol, and in sulphuric ether; but when digested 
in dilute muriatic or sulphuric acid, a portion was taken up 
forming a brown solution. I regard this soluble portion as a 
modification of the colouring matter produced by the opera- 
tion of heat: the insoluble residuum had the properties of 
albumen. 
* Haller Elem, Physiolpg. Vol, I. p. 5s, 
