310 Dr. L. C. Wooldridge. [Jan. 31, 



the clot commencing in the middle of the portal trunk, and extend- 

 ing into all the branches of the portal in the liver. 



Dog II. Weight 16 Ibs. 7'5 c.c. of the fluid injected, bnt ten 

 times diluted with alkaline salt solution. The injection was slow, 

 taking from three to four minutes. The dog was killed. There was 

 absolutely no trace of clotting in any vessel. 



As regards diet the animals were in similar conditions. 



Experiment 2. 



Used the watery extract of thyrnus. precipitated with acetic acid, 

 and the solution of this precipitate in alkaline half per cent. NaCl 

 injected. 



Dog I. Weight of dog, 14 Ibs. Injected rapidly 7 c.c. of solution. 

 The animal ceased to breathe instantly and never breathed again. 

 The heart continued to beat for several minutes. The right heart, the 

 whole of the pulmonary artery and veins, and the left heart one solid 

 clot. 



Dog II. Weight of dog, 13^ Ibs. 7 c.c. of the same solution 

 injected, but diluted ten times with alkaline salt solution ; the injec- 

 tion slow, occupying three to four minutes. Dog killed. Absolutely 

 no trace of clotting anywhere. 



It is seen from the above experiments that a substance added 

 rapidly to the circulating blood produces a pronounced effect ; added 

 comparatively slowly and diluted, but in the same quantity propor- 

 tionate to the weight of the animal, it produces no effect at all. 



The obvious effect may be local, t.e., occur where the sudden 

 admixture of fluids takes place, i.e., in the heart; or it may be remote 

 and take place in the portal vein. 



The phenomenon appears to resemble somewhat the so-called 

 "mass influence " (massenwirkung) of chemists. 



A sudden admixture of a sufficient quantity of this substance with a 

 given quantity of blood poisons the blood ; the same conditions would 

 be produced if instead of the injection being sudden the blood were 

 circulating more slowly. In this case, also, a given quantity of the 

 blood would in a given time receive a larger quantity of the fluid 

 than if the blood were rapidly circulating. For the present I am 

 speaking of the blood being affected by its showing an obvious 

 change, that is clotting; and I know, from previous experiments, that 

 to produce this change a certain quantity of the fibrinogen must be 

 added to the blood, i.e., the larger the dog, and consequently the more 

 blood, the more of fibrinogen must be injected. 



The present experiments show that to affect the blood a certain 

 quantity of the substance must reach the blood within a given time, 

 and this effect may obviously be obtained either by rapid injection or 

 by the current of blood being slow in the neighbourhood of the vessel 



