70 Dr. L. C. Wooldridge. A New Constituent of the [Jan. 8, 



It must be understood that the plasma, previous to the passage of 

 the C0 2 , is quite free from fibrin ferment, so that there can be no 

 question of the ferment being mechanically removed by the pre- 

 cipitate. 



Moreover, that it is really the body removable by cold which gives 

 rise to the fibrin ferment, and not any second body which is mechani- 

 cally carried down with the former, is shown by the fact that the 

 diffusion of a large quantity of inert finely- divided precipitate through 

 the plasma, and its subsequent removal by the centrifuge, does not in 

 any way do away with the power of the plasma to clot. 



It is therefore justifiable to assume that when pepton plasma clots 

 readily and completely with C0 2 , it must contain this new body in 

 some quantity, and that when it will not clot, or only very imperfectly, 

 after repeated treatment with C0 2 or dilution, this new body must be 

 present in very small quantity. 



Now I have found that the behaviour of pepton plasma with C0 2 

 varies very considerably with the diet on which the animal is fed, and 

 whether the animal is fasting or has recently been fed. In some cases 

 it clots readily, in others practically not at all. 



Out of eight dogs fed on very lean meat only one gave a plasma 

 which clotted at all fully, and in this case the clotting went on for 

 two days. From all the others the plasma, in spite of repeated treat- 

 ment with C0 2 , only gave rise after two or three days to a scarcely 

 perceptible fibrin membrane. The animals were killed about eighteen 

 hours after the last meal. 



Of six dogs fed on fat and meat for several days all gave a plasma 

 which clotted rapidly and fully in from twenty minutes to one hour 

 after the C0 2 treatment. The animals were killed about eighteen 

 hours after being fed. 



Of two dogs fed on bread and meat both gave a readily coagulable 

 plasma. 



One day's feeding on fat does not produce any effect ; that is the 

 blood of a dog thus fed behaves like that of a dog fed on a lean meat. 



A dog fed for some days on fat and meat, was for five days previous 

 to being killed put on fat alone; as a consequence it practically 

 starved, as it ate scarcely anything. The blood from this dog clotted 

 very incompletely. 



Simple starvation for three days did away with the influence of fat 

 in another case. 



These results only hold good for dogs in health. In a dog with a 

 suppurating wound, kindly placed at my disposal by Mr. Horsley, 

 the plasma, in spite of a lean meat diet, clotted with very great 

 rapidity, and contained an enormous quantity of the new body. All 

 the other dogs were healthy, but were badly nourished when they 

 came into my hands. 



