intervertebral Substance in Fish and Quadrupeds. 185 
small quantity of ammonia being at the same time evolved. 
Muriatic acid did not produce any immediate precipitation in 
this alkaline solution. 
The effect of these re-agents, evidently proves the non- 
existence of gelatine in this fluid ; it would also appear that it 
contains no albumen, unless the effects produced by muriatic 
acid and by the oxymuriat of mercury and of tin, be regarded 
as indications of that substance. 
It seems to approach nearer to mucus or mucilage, than to 
any other animal fluid.* 
When the fluid is evaporated in a temperature not exceed- 
ing 220 0 to half its bulk, an opaque substance in the form of 
bluish white filaments, gradually separates. A thin semi- 
transparent pellicle forms at the same time upon the surface, 
which, when removed, is soon succeeded by another. These 
pellicles were dried on bibulous paper. 
The fluid part, remaining after the separation of the fila- 
mentous substance and pellicles, afforded a very distinct 
yellowish cloud, with solutions containing tannin. It was 
somewhat turbid, but did not form any deposit. In other re- 
spects, it nearly resembled the original fluid before evaporation. 
The filaments which appeared during evaporation, were 
separated by passing the fluid through a piece of fine muslin. 
They resembled albumen imperfectly coagulated, not only in 
appearance, but in most of their chemical properties. 
When the fluid began to putrify, a considerable quantity 
of the same substance separated spontaneously. 
* By mucus of animals, I mean a glary fluid, which does not mix readily with 
water, which is neither coagulated by heat or acids, and which does not form a pre- 
cipitate with solutions containing tannin. 
MDCCCIX. B b 
