39° Mr. Hatchett's Experiments on Zoophytes, 



are substances really soluble,' although in so slight a degree 

 as to approach insolubility; and that thus the prevalent opinion 

 has arisen concerning the insolubility of coagulated albumen 

 in boiling water. 



Neither is the putrefaction of the water in which the bodies 

 abovementioned have been boiled, a proof that any other than 

 their real substance has been dissolved ; for this putrefaction 

 appears to depend on its attenuated and diluted state, more 

 than on any other cause. Tortoise-shell, nail, quill, and similar 

 bodies, certainly are not liable to putrefaction ; neither is albu- 

 men, when in the inspissated semi-transparent state. 



This last substance also, when merely coagulated, does not 

 easily putrefy ; for I kept it, when it was soft, white, and 

 coagulated, in water, during the whole of the month of last 

 April, without finding that it became really putrid : towards the 

 latter part of the time, it had rather a disagreeable smell ; still, 

 however, it was far from being absolutely putrid. 



But albumen which has not been coagulated, or which has 

 been diluted and shaken with a quantity of cold water, begins 

 in a very few days to be putrid; liquid albumen, therefore, 

 enters easily into putrefaction, although it is the reverse with 

 that which is dense and solid : and, from a comparison of the 

 preceding experiments upon tortoise-shell, quill, nail, &c. with 

 those made on albumen, I am induced to believe, that the 

 former bodies are essentially composed of albumen, modified 

 by the various effects of organization, and reduced to a state 

 of density far exceeding that which is produced by simple 

 inspissation. 



And, although the bodies, which of late have been particu- 

 larly mentioned, appear to consist principally of albumen, with 



