Dr. Buchanan <m the Fibrin contained in the Animal Fluids. 181 



from sugar was long ago shown by Huber, and has recently been hap- 

 pily brought forward by Liebig, in evidence of the purposes which 

 sugar and starch fulfil in the respiratory economy. The intermediate 

 position which fat sustains between sugar and wax, renders the yiews 

 of Liebig, with respect to the production of fat from starch, highly 

 probable ; and I am strongly inclined to infer that cholesterin occupies 

 a lower stage in the reducing process, from the fact of my having 

 obtained from it different products, and one approaching naphtha in 

 its odour and apparent composition, and from various other considera- 

 tions, which I hope soon to be able to detail more fully. The pos- 

 sibility of the derivation of turpentine oils and resins from starch and 

 sugar scarcely requires to be pointed out 



Note. — Since writing the above, the observation by the French 

 chemists of the existence of stearic acid in wax, confirms the plausi- 

 bility of Liebig's view of the analogy of fat and wax, and strengthens 

 the opinion which I have long entertained, that cholesterin is the wax 

 of mammiferous animals.. 



29th Marchf 1843, — -The Vice-Pkesident in the Chair. 



The report on the present state of Vital Statistics in Scotland 

 was read, and referred to a committee.. 



XXXIV. — On the Fibrin contained in the Animal Fluids, the Mode in 

 which it coagulates^ and the Transformations which it undergoes. By 

 Andrew Buchanan, M.D., Professor of the Institutes of Medicine^ 

 University of Glasgow, 



I. — characters of the fibrin in the antmal fluids. 



The substances named Fibrin by physiologists do not seem to be all 

 identical in chemical composition. The buffy coat of the blood has been 

 recently ascertained to comport itself quite differently with chemical 

 reagents, from the substance which forms the basis of muscular fibre. 

 The same is probably true of all the substances to be here spoken of, as 

 they are more analogous to the former than to the latter modification 

 of Fibrin. Still farther, they probably vary in chemical composition 

 in the successive changes of condition which they are observed to 

 undergo. 



The substances, to which I wish here to direct your attention, are 

 distinguished by the following characters. They all form part of 

 certain animal fluids, of the serous or albuminous class, from which, 

 when withdrawn from the body, they separate spontaneously, concreting 



