THE BLOOD. 5 



experiments hereafter to be related, where the blood in the 

 living animal, whilst at rest, was found both to coagulate and 

 to separate. 



It is well known, that the crassamentum consists of two 

 parts, of which one gives it solidity, and is by some called the 

 fibrous part of the blood, or the gluten, but by others with 

 more propriety termed the coagulable lymph ; and of another, 



thermometer, as usual, was employed. The blood experimented on 

 was taken from the 'jugular veins of troop horses; it was put into tubes 

 of thin glass, about three eighths of an inch in diameter, and then 

 plunged into water heated to the required degrees. Different neutral 

 salts were used; but most commonly half an ounce of Glauber's salt to 

 six ounces of blood, being the mixture mentioned by Hewson. 



a. It is extremely difficult to ascertain the precise degree of heat 

 most favorable to the coagulation of a spontaneously coagulable fluid ; 

 but one cause of discordance as to the effects of higher temperatures 

 has arisen from different methods of experimenting. A cup of blood 

 put into water at 1 50, as in Mr. Hunter's experiment, will coagulate 

 before acquiring that heat, whilst blood in a thin tube, in the same water, 

 may have its property of spontaneously coagulating quite destroyed. 



b. Different portions of blood were subjected to every degree of heat, 

 from 139 to 151, and in every trial the blood was fluid at the end of 

 twenty miuutes. It never coagulated regularly, though it did some- 

 times partially; and at the higher degree there was, towards the bottom 

 of the tube, a grumous, and sometimes a stiff" and brownish paste, 

 chiefly of corpuscles, leaving no fibrin behind when washed in a linen 

 bag. The coagulable lymph was liquid at the top of the blood in the 

 tube. 



c. Some liquor sanguinis skimmed from fluid blood, and kept at a 

 heat of 139 for twenty minutes, never coagulated. Another portion 

 of liquor sanguinis at 148-150 was fluid at the end of twenty-three 

 minutes, but coagulated in twenty-eight, when it was more opaque than 

 a portion of the same fluid which had coagulated in the air at 60 in 

 fourteen minutes. 



d. At a heat of 122, 123, 124, 125, and 126, coagulation of 

 blood, and of liquor sanguinis separately, was hastened about two mi- 

 nutes, and rather more at the lower than* at the higher degrees. 



e. A mixture of blood and salt, or of liquor sanguinis and salt, will 

 not coagulate at any degree of heat short of that which coagulates the 

 albumen, commencing at about 125. 



f. It is true that in salted liquor sanguinis at 124-127, though a 

 great part of the mixture remains fluid, a little curdy, flaky, filamentous, 

 and opaque precipitate forms, which is probably what Hewson describes 

 in his Experiments vn and ix as coagulation ; though it differs from the 

 spontaneous setting or jellying into a transparent mass of a mixture of 

 salted liquor sanguinis and water. 



g. As shown in Note xvn, serum mixed with Glauber's salt coagulates 



