654 THEORY OF COAGULATION. 



That coagulation is a vital process, analogous 

 to that by which blood is converted into the dif- 

 ferent organs, and owing to the same cause 

 which enables the muscles to contract, was fully 

 recognized by John Hunter, who demonstrated, 

 by an admirable series of experiments, that when 

 effused into healthy divided parts, it becomes 

 penetrated with innumerable vessels that may be 

 injected by injecting the neighbour ingarteries, 

 causing wounds to heal by the first intention, and 

 plugging up divided vessels.* He also maintained 

 with Hewson, that the process of coagulation is 

 accelerated by an increase of temperature, and 

 retarded by cold ; that the colour and coagulating 



solutions of opium, belladonna, strychnia, nicotin, sulphate of 

 morphia, digitalis, aconite, hemlock, tartarized antimony, bichlo- 

 ride of mercury, nitrate of copper, and by nearly all the neutral salts, 

 except in very small proportions, although most of the latter change 

 it to a florid hue; and that while some of the above medicines 

 precipitate the albumen of the blood, others dissolve its fibrin. 

 Magendie has also shown, that by injecting seven grains of oxalic 

 acid into the jugular vein of a dog, he was attacked with difficult 

 breathing, small and frequent pulse, prostration of strength, fol- 

 lowed by coma and death in a few hours ; and that the same fatal 

 effects were produced by injecting an ounce of the mildest neutral 

 salts into the veins. (Lancet for 1839.) 



* We also learn from the researches of Prevost and Dumas, that 

 when a small quantity of blood from a living animal is immediately 

 placed between thin pieces of talc, the red particles may be seen 

 with a good microscope to arrange themselves in lines, or series 

 and aggregates, that resemble chaplets of beads, (a process which 

 must be regarded as an imperfect species of organization, and as 

 the result of its last remainder of vitality.) (Ann. des Sciences 

 Naturelles, tome xii.) 



