76 PROPERTIES OF 



From this conclusion I went further, and conjectured that 

 even temporary exertions of strength in the blood-vessels might 

 alter the properties of the lymph ; to which opinion I was led 

 by having observed the blood sizy in the case mentioned in 

 Experiment 20th, where great weakness soon followed the eva- 

 cuation ; and likewise from having observed, that the struggles 

 of dying sheep seemed to alter the lymph (L). 



So that upon the whole the opinion agrees with all the ap- 

 pearances, and is supported by all the differences in strength 

 that occur in the various deviations from the standard of health : 

 for when the vessels act more strongly than they do in health, 

 the lymph is proportionably more thinned, and is less disposed 

 to concrete; and when the vessels act more weakly than in 

 health, then the lymph is proportionably thickened, and is more 

 ready to concrete. Is it not therefore probable that the dif- 

 ferences we observe in the thickness or thinness of the lymph, 

 and in its being more or less disposed to coagulate, are owing 

 to these differences in the strength of the blood-vessels ? For 

 such alterations in the strength of the blood-vessels are always 

 connected with those of the lymph, and we can observe no other 

 circumstance connected with those changes of the lymph that 

 can at all explain them. 



And although it must be admitted that it is very difficult 

 to conceive how the blood-vessels should do this, yet I should 

 hope that ingenious men would not merely on that account 

 reject my conclusion ; but would consider, that as it is deduced 

 from a number of experiments, as it agrees with all the appear- 

 ances, and as it leads to an explanation of many of them which 

 we cannot otherwise account for, it may be well founded, al- 

 though it be difficult to be conceived ; for there may be powers 

 in the animal economy that are not yet dreamt of in our phi- 

 losophy. 



This observation of the properties of the blood depending 

 on the state of the vessels, besides explaining many morbid 

 appearances, leads to a further application ; for we may thence 

 be led to advance more rational and more certain rules for the 

 treatment of hemorrhages. For as hemorrhages seem to be 

 stopped, partly by a contraction of the bleeding orifices, and 



(L.) See Note xxiv. 



