i86 
Mr. Home on the Nature of the 
This substance was insoluble in water, and when boiled for 
a few minutes in that fluid, it became whiter, harder, and 
more opaque. 
It underwent the same change in alcohol, and when boiled 
in alcohol, or in dilute muriatic acid, it became still more firm, 
and appeared like perfectly coagulated albumen. 
In this state it was soluble in a solution of pure potash, 
forming a saponaceous compound, which was decomposed by 
dilute muriatic acid, a white flaky precipitate being formed. 
It possessed the other properties which Mr. Hatchett has 
enumerated as belonging to coagulated albumen.* 
When the pellicle, which had formed on the surface of the 
fluid during evaporation, was nearly dry, it became somewhat 
tough and elastic ; it was semi-transparent, and of a dirty 
white colour. 
When boiled for some time in water, about three fourths 
of it were found to be soluble in that fluid, the remainder, 
when separated by filtration, possessed the properties of the 
albuminous substance already mentioned. 
The solution afforded a copious precipitate with solutions 
containing tannin. It was not at first affected, either by oxy- 
muriat of mercury, or of tin ; but after twenty four hours, a 
slight deposit took place. 
Although these re-agents indicated the presence of a sub- 
stance having the properties of pure gelatine in solution, yet 
it could not be brought to gelatinize by the usual method of 
evaporation. 
From these experiments it would appear, that the inter- 
vertebral fluid, is of a peculiar nature ; that in its original 
* Vide Phil. Trans. 1800. 
