4 METHOD OF ANALYZING THE BLOOD. 



Water in 1000 parts of serum. 



Solid constituents in 1000 parts of serum. 



Solid constituents in serum of 1000 parts of blood. 



Albumen and extractive matters. 



Fixed saline constituents in 1000 parts of serum. 



Fibrin in 1000 parts of blood. 



We have now sufficient data from which to calculate the dried blood-corpuscles, 

 moist blood-corpuscles, and liquor sanguinis. 



To ascertain the weight of the dried blood-corpuscles, add together the weights 

 of the fibrin and the solids of the serum contained in 1000 parts of blood, and 

 deducting the sum of them from the weight of the entire solid matter, which con- 

 sists of fibrin, solids of the serum, and blood-corpuscles; the difference will repre- 

 sent the proportion of the latter in 1000 parts of blood. 



Another method is founded upon the fact, that a solution of the sulphate of soda 

 possesses the property of rendering the blood-corpuscles capable of being retained 

 upon a filter. This method was first applied by Figuier, and afterwards improved 

 by Dumas and Hcifle. Defibrinated blood is treated with eight times its volume of 

 a concentrated solution of Glauber's salts, and filtered, the residue on the filter is 

 rinsed with the same solution, a stream of oxygen is passed through the mass of 

 blood-cells on the filter, and, finally, the mass of blood-cells is either coagulated 

 with hot water, upon the filter, or washed off into tepid water and coagulated by 

 boiling. 



This method is not to be depended upon in practice, because some of the blood- 

 corpuscles always pass through the filter, and it is impossible to determine whether 

 all the serum is actually separated in this manner, and also because the solution of 

 the sulphate of soda passes into the corpuscles by endosmosis, whilst the organic 

 constituents of the corpuscles pass out. 



F. Simon's method of finding the quantity of the blood-corpuscles directly, is not 

 only tedious, but also wanting in accuracy. 



C. Schmidt, to whose intelligence and indefatigable researches physiological 

 chemistry is indebted for many brilliant discoveries, first attempted to determine 

 the relation of the moist blood-cells to the intercellular fluid, or liquor sanguinis. 

 He found that 4 is the constant factor by which we may calculate the moist blood- 

 cells from the dry blood-corpuscles. If we multiply the number of dry blood-cor- 

 puscles by 4, we obtain the quantity of fresh blood-cells. Subtracting these from 

 1000, we have remaining the amount of liquor sanguinis in 1000 parts of blood. 



Having briefly described the method by which these important constituents are 

 obtained, we will next state the manner in which the results are exhibited. The 

 constituents of 1000 parts of blood are always presented in two lights. 



1st. The fixed saline matter of the dried blood-corpuscles is subtracted from 

 their weight, and we have remaining the dried organic matter of the blood-cor- 

 puscles in 1000 parts of blood. In like manner, the fixed saline constituents of the 

 serum of 1000 parts of blood are subtracted from the solid matter of the serum of 

 1000 parts of blood, and we have remaining the dried organic portion of the albu- 

 men and extractive matter. It is evident that, if the analysis has been properly 



