172 OF THE BLOOD. 



coagujable proportion of the Albumen and Corpuscles, the coagulation being 

 induced as before, and the filtered residue again serving for the determination 

 of the extractive and soluble salts. The fatty matters may be determined by 

 boiling in ether, for a sufficient length of time, portions of the fibrin, of the 

 albumen, and of the coaguluin of the whole blood, separately. In summing up 

 the result, the amount of the various solid matters is calculated for 1000 parts 

 of Blood ; the remainder is then the watery part of the blood. From the propor- 

 tion of albumen to water in the serum, the amount of albumen in the whole mass 

 of the blood can be calculated by its quantity of water; and the amount of albu- 

 men and corpuscles taken together having been determined, that which remains 

 after the deduction of the albumen represents the corpuscles. 1 



154. Both of the foregoing methods are open to the objection, that the albu- 

 minous and other constituents of the Serum are reckoned in the calculation as 

 being equally present in the whole water of the blood. Now as the moist Corpus- 

 cles, according to Lehmann, constitute fully half the mass of the blood, and as 

 they do not contain the albuminous elements of the serum, and have salines 

 peculiar to themselves, it is obvious that the constituents of the Serum will be 

 estimated far too high, and the residue, which expresses the solid matter of the 

 Corpuscles, as much too low. In order to avoid this source of error, by separat- 

 ing the corpuscles from the serum, so as to be able to form a direct estimate of 

 their amount, it has been proposed by M. Figuier to filter the defibrinated blood 

 after having added to it a solution of sulphate of soda, the effect of which is to 

 separate the corpuscles from the serum without causing them to discharge their 

 contents. This method has been adopted by Dumas, Hofle, and Grorup-Besanez, 

 and was employed in the third and fourth of the analyses already cited ( 152); 

 it would appear from these, however, to produce a still further reduction in the 

 proportion assigned to the corpuscles ; and for this it is not difficult to account, 

 when it is borne in mind that the saline solution will tend to empty them of 

 their contents, unless its specific gravity be accurately adjusted ( 139). Again, 

 it must be borne in mind that the preceding methods of analysis give no account 

 whatever of the Salts contained in the Corpuscles, which, as we have seen, are 

 very different from those of the Serum; and these can only be determined by 

 the incineration of the whole mass of the blood. Other methods which have been 

 proposed for the more precise quantitative determination of the principal con- 

 stituents of the Blood, are not only tedious and complex, but involve the use of 

 various reagents, which may themselves induce considerable changes in the " be- 

 havior" -of its organic components ; 2 and in the present state of our knowledge, 

 therefore, it is impossible to arrive at any other than an approximative estimate 

 of their respective amounts. The following is founded on the comparative ana- 

 lyses of the Serum and Liquor Sanguinis already cited from Prof. Lehmann 

 ( 142) ; it being assumed that the moist Corpuscles form half of the entire 

 volume of the blood. This, in his opinion, is rather beneath than above the 

 actual average, which he considers to be 512 parts in 1000 ; the limits of varia- 

 tion in health being about 40 parts on either side. By halving the numbers in 



1 It is a curious indication of the uncertainty of the results of analyses conducted upon 

 principles essentially the same, that whilst, in the first of the cases above cited ( 152), the 

 proportion of corpuscles given by Becquerel and Rodier's method was almost identical 

 with that given by the method of Scherer, there was a marked difference in the propor- 

 tions of albumen and extractive ; whilst in the second, the proportion of albumen being 

 almost identical in the two analyses, the amounts assigned to the corpuscles and to the 

 extractive respectively differed by no less than 18 parts in the 1000, for each of these 

 constituents. 



2 For an account of the methods of Berzelius, Denis, and Simon, see the "Animal 

 Chemistry" of the last-named author (translated by Dr. Day), pp. 143, et seq., Am. Ed. 



