24 PROPERTIES OF 



above-mentioned times will, I believe, be found to be those at 

 which the blood congeals in the veins of healthy dogs : and as 

 I have found, by experiments, that the blood of a dog and of 

 the human subject in "health jellies out of the body, nearly in 

 the same time, that is, it begins in three or four minutes, and 

 is completed in seven or eight ; I should therefore conclude 

 that the blood in the veins of the human body coagulates 

 nearly at the same period with that of a dog (xiv). But it 

 may be necessary to add here that, from experiments which I 

 have made, I have reason to believe that the* time at which 

 the blood coagulates, is different in different constitutions, and 



death, the sinking of the corpuscles being favoured by their increased 

 tendency to aggregation in connexion with disease, and by the slowness 

 with which the blood coagulates (see Notes x and xxin). Mr. Paget d 

 has shown that the disposition of the parts of the blood in the dead body 

 is the same as if the blood had coagulated as slowly and separated in a 

 basin ; and that the clot is so regularly pale in its upper part, and coloured 

 by the red corpuscles at the bottom, that the fact might be available in 

 medico-legal inquiries as to the position of the body in the first hours 

 after death. But the separation of the corpuscles is often imperfect, or 

 does not take place at all, as I have witnessed in some cases of sudden 

 death. Dr. Davy 6 found the clot broken up in the ventricles, as if its 

 coagulation had preceded death. The relative position of the fibrin 

 and coloured matter in the heart and great vessels after death, did not 

 escape the notice of the accurate Petit. f 



Fibrinous clots are occasionally formed in the heart and blood-vessels, 

 and become softened there, during life. The softening is generally, 

 but not always, in the centre of the clot. Coagulation of blood in the 

 veins, often followed by softening of the clot, is a common disease 

 in the human subject, especially in connexion with oedema of the lower 

 limbs. This softening of fibrin is very frequent in the veins of horses. 

 It does not appear to be of an inflammatory nature, though I apprehend 

 that it has been generally confounded with phlebitis. g 



(xiv.) I have found that the blood of a dog generally coagulates 

 rather sooner than that of man. Mr. Thackrah a infers from his ex- 

 periments that coagulation commences sooner in the blood of small and 

 weak animals than in that of the large and strong. Dr. Blundell b states 

 that the blood of the dog, sheep, and ox, coagulates sooner than the 

 human blood. 



<* Lond. Med. Gaz. i, 1840-1, p. 613. s On the Softening of Fibrin, Med. Chir. 

 e Researches, ii, 196. Trans, vol. xxii. 



f Hist. de 1'Acad. Roy. des Sciences, a On the Blood, ed. 1834, p. 154. 



annee 1732, p. 393. h Med. Chir. Trans, ix, 67. 



