ON THE ANIMiL FLUIDS £f 



^he foregoing pages of rejoinder will, 1 trust, 9ave me the Substances 



trouble of many intended remarks on Dr. Marcet's paper, ^^"mal fluids. 



independently of its relation to the questions at issue* A few 



comments only I shall now beg to be allowed to deliver. 



1. The animal matters in the fluids examined are stated - \ 



.. , • iii ii • The animal 



to be of two kinds: viz. coagulable or albuminous matter, matter in the 



and what the author calls muco-extractive, I do not at all fluids of one 



, . 1.1 • i kini onlv. 



object to the experiments, but appeal to competent judges* 



whether it is not unjust to make this distinction. The evi- 

 dence of the coagulable matter is from the visible coagula- 

 tion by calorific, and some reagents, but if there be not a 

 due proportion of it to the water in which it is dissolved, 

 such evidence is not obtainable. This may be easily proved, 

 and as I apprehend I have shown in my published papers, 

 by a kind of synthetic experiment. For example: se- 

 rum of blood, or any other known coagulable fluid, may be 

 so diluted with water, as to afford no clear proof of its pre- 

 sence by coagulation on applying calorific, although such, 

 an effect may be reasonably inferred on probable grounds 

 from the disturbance of transparency, or cloudiness. And, 

 as far as I have found by experiment, coagulable matter 

 so diffused, on being collected by evaporation to dryness, is 

 scarcely coagulable by calorific ; so that the whole of any 

 given quantity of animal coagulable fluid by such treat- 

 ment was rendered uncoagulable. According to my trials 

 too, there always remained, on coagulating serum and other 

 analogous fluids, a small proportion of animal matter dis- 

 solved in the watery part, which differed in no respect from 

 the matter left on evaporating water containing a certain 

 small and uncoagulable proportion of serum added to the 

 water as above stated. But these dilute solutions, which 

 appear uncoagulable, denote the presence of aaimal matter 

 to the test of tannin. It was probably this property, and 

 the animal matter afforded by evaporation, which induced 

 some chemists to conclude, that a different kind of animal 

 substance from coagulable, such as gelatinable, existed in 

 the serum of blood. Hence I conclude, that the two grains 

 of what Dr. Marcet calls muco-extractive matter, afforded 

 by 500 grains of serum, after separating 44 grains of albu- 

 men or coagulable matter, is this matter rendered uncoagu- 

 lable by dissolution. And hence too I conclude, that the 



animal 



