64 THEBLOOD. 



5. Imperfect aeration, as in the blood of those who die by 

 asphyxia. 



6. In inflammatory states of the system, the blood coagulates 

 more slowly although more firmly. 



7. Coagulation is retarded by exclusion of the blood from 

 the air, as by pouring oil on the surface, &c. In vacuo, the 

 blood coagulates quickly ; but Prof. Lister thinks that the 

 rapidity of the process is due to the bubbling which ensues 

 from the escape of gas, and to the blood being thus brought 

 more freely into contact with the containing vessel. 



The coagulation of the blood is prevented altogether by the 

 addition of strong acids and caustic alkalies. 



It has been believed, and chiefly on the authority of Mr. 

 Hunter, that, after certain modes of death, the blood does not 

 coagulate ; he enumerates the death by lightning, overexertion 

 (as in animals hunted to death), blows on the stomach, fits of 

 anger. He says, "I have seen instances of them all." Doubt- 

 less he had done so ; but the results of such events are not con- 

 stant. The blood has been often observed coagulated in the 

 bodies of animals killed by lightning or an electric shock ; and 

 Mr. Gulliver has published instances in which he found clots 

 in the hearts of hares and stags hunted to death, and of cocks 

 killed in fighting. 



Chemical Composition of the Blood. 



Among the many analyses of the blood that have been pub- 

 lished, some, in which all the constituents are enumerated, are 

 inaccurate in their statements of the proportions of those con- 

 stituents ; others, admirably accurate in some particulars, are 

 incomplete. The two following tables, constructed chiefly from 

 the analyses of Denis, Lecanu, Simon, Nasse, Lehmann, Bec- 

 querel, Rodier, and Gavarret, are designed to combine, as far 

 as possible, the advantage of accuracy in numbers with the con- 

 venience of presenting at one view, a list of all the constituents 

 of the blood. 



Average proportions of the principal constituents of the blood 

 in 1000 parts: 



Water, 



lied corpuscles (solid residue), 

 Albumen of serum, 

 Saline matters, .... 

 Extractive, fatty, and other matters, 

 Fibrin. . 



784. 



130. 



70. 



6.03 



7.77 

 2.2 



1000. 



