90 PROXIMATE ANALYSIS OF 



tions of the vital fluid, science would be more benefited by the 

 investigation, than by the performance of a few very perfect 

 anatyses, which did not tend to elucidate any particular point. 



The best methods for the analysis of the various animal sub- 

 stances which are treated of in this volume, will be found in 

 their proper places. We will, however, give a preliminary 

 sketch of the course that should be adopted, if a fluid, of whose 

 nature we are ignorant, be placed in our hands for analysis. 



Such a fluid may contain, 



I. The protein-combinations : fibrin, albumen, casein, glo- 

 bulin, i 



II. P 1)171. 



III. Extractive matters : water-extract, spirit-extract, alco- 

 hol-extract, and their proximate constituents. 



IV. Sugars : Diabetic sugar, and sugar of milk. 



V. Bilin, with the products of its metamorphosis. 



VI. Urea. 



VII. ll\ve fats : olein, stearin, margarin, butyrin, cholesterin, 

 and serolin. 



VIII. Colouring matters : the pigments of the blood and bile. 



IX. The acids of the animal body : 



a. Fatty acids. 



j3. Other organic acids. 



-y. Inorganic acids. 



X. The bases of the animal body. 



General physical analysis. 



1. If the fluid contain flocculi or coagulated matters, they 

 are generally composed of fibrin, which by its spontaneous 

 coagulation frequently includes other substances in a state of 

 mechanical suspension. The whole fluid will sometimes as- 

 sume a gelatinous consistence, as has been observed in certain 

 products of exudation; in other cases it presents an appearance 

 of separation, one portion assuming the form of a cake or clot, 

 whilst the remainder continues fluid, as in the well-known in- 

 stance of the blood. On placing these clots, &c., in distilled 



' Crystallin, or the modification of casein that occurs in the crystalhne lens, is not 

 included in this scheme, since it is not known to occur in any of the animal fluids. 



^ [I'vin being tritoxide of protein, must now be regarded as a true protein-com- 

 pound. The binoxide of protein nmst also be included in the same category.] 



