164 Mr Larmor, On the most general type of [May 4, 



mentions that if, in the rabbit, the coeliac and superior mesenteric 

 arteries be tied, the blood, if collected after about four hours, will 

 not clot for about two hours. He intimates his intention of en- 

 quiring further into this matter, since his assertion is based on 

 two experiments only; but he has as yet written nothing more 

 on the subject. 



In April, 1890, I commenced repeating his experiments, but 

 I have not yet had time to investigate the matter completely. 

 However, in six experiments in which the coeliac and superior 

 mesenteric arteries were ligatured, the blood collected always 

 clotted in less than two hours : in fact, generally under ten 

 minutes. In one case only were twenty minutes required before 

 the clotting became evident. It is true that the time was slightly 

 lengthened, since, normally, clotting takes place in 3-5 minutes ; 

 and the clot was decidedly not so firm as usual. The experiments 

 were performed as Bohr describes, except that in the first two, 

 the abdomen was opened in the middle line, instead of at the 

 side. After four hours, the animal being under chloroform during 

 the whole time, the blood was collected from the carotid. Bohr 

 states that his animals were apparently as well at that time as at 

 the beginning : I always found the stomach partially self-digested 

 and the intestines becoming gangrenous, and there was a great 

 fall of temperature. 



The occlusion of the arteries by the ligature was always tested 

 by injecting the animal after death, and, with one exception in 

 which the coeliac artery let the injection through, was found to be 

 complete. Thus it appears that some slight though evident effect 

 on the clotting may be produced by stopping the circulation 

 through the stomach and intestines, but it is generally not as 

 marked as in Bohr's two experiments. 



May 4, 1891. 



Peof. G. H. Darwin, President, in the Chair. 



The following Communications were made to the Society : 



(1) The most general type of electrical waves in dielectric 

 media that is consistent with ascertained laws. By J. Larmor, M.A., 

 St John's College. 



It was explained that Maxwell's hypothesis of complete circuits 

 reduces the whole of electrodynamics to the ascertained Ampere- 

 Faraday-lSfeumann laws for such circuits, as it completely defines 

 the character of the electrostatic polarisation which must be 

 postulated as a part of the theory. The question as to how far 

 the theory of electrodynamics may depart from this simple form 



