Inquiry into the Nature and Pro2)erties of the Blood. 373 



strongly, Mr. H. says, the disposition of the fibrin to coagulate 

 is proportionably diminished. On the contrary, when an animal 

 is bled to death, or when the vessels are acting witli the lowest 

 degree of strength, the blood was more and more disposed to 

 coagulate in proportion as the animal was reduced. Tempoi'arv 

 exertion of strength, moreover, even the struggles otthe dying 

 animal, he thought might lessen this tendency for a short time ; 

 ibr the struggles of dying sheep, he says, seemed to alter the 

 lymph or fibrin : and he adds, that although it must be ad- 

 mitted it is very difficult to conceive how the blood-vessels 

 should do this, yet he hopes that ingenious men will not merely 

 on that account reject his conclusion ; but would consider, that 

 as it is deduced from a number of experiments, as it agrees with 

 all the appearances, and as it leads to an explanation of many 

 of thein which we cannot otherwise account for, — it mav be 

 well founded, although it be difficult to be conceived. For 

 there may be powers in the animal oeconomy that are not yet 

 dreamt of in our philosophy. 



Mr. Hewson spent much labour and time on these points ; 

 and we find that he confirms the testimony of some of the 

 writers of the last century, in stating that the sulphate and 

 muriate of soda and the nitrate of potash wei'e among the most 

 powerful salts in counteracting this change ; so much so in- 

 deed, as Dr. Bostock has quoted, that if we add to a portion 

 of blood rather less than l-20tli of its weight of any one of 

 them, the coagulation does not take place : on which re- 

 markable effect Dr. B. remarks, that this cannot be owing 

 to any tendency in the salt employed to dissolve the fibrin, 

 because the neutral salts do not possess this property ; at the 

 same time that potash, which is the proper solvent of fibrin, 

 has less power in retarding its coagulation. 



The mere dilution of the blood with a sufficient quantity of 

 water will effectually prevent its spontaneous coagulation, which 

 is attributed to its particles being thereby removed to so great 

 a distance from each other as to be placed beyond the reach 

 of their mutual attraction. The coagulability of the fibrin is 

 also affected and indeed destroyed by electricity and light- 

 ning; for in persons who have been killed by lightning, the 

 blood is not coagulated at all, but remains perfectly fluid : nor 

 is this the only remarkable ertect; their muscles also remain 

 as flexible as ever, and the rigidity and stiffness which is the 

 common consequence of death does not take place*. But 

 what may be regarded as more extraordinary still, this coa- 

 gulation of the blood is likewise prevented by a blow on the 

 pit of the stomach when causing sudden death, instances of 

 • Henry's Elements of Chemistrv, vol. i. p. 3:20. 



which 



