( 226 ") 



there appeared lucli a membrane or film on tlie fiuTace of the waten 

 that nothing could be diftinguifhed in tlic fluid, except fome excel- 

 fively minute particles iwiniming in the water in fuch multitudes, 

 that, if fome of them had not collected together in the form of falts, 

 I could not have dii'covered them. And, I could not fufficiently ad- 

 mire, that from i'o fmall a fragment of the root, fucli a quantity of 

 falts had palled intotiie water. 



After this water had flood undifturbed for fome time, and the 

 films on it were fubfided, I put a drop of it, about the fize 

 of a pin's head, into a clean glafs, and mixed with it lome blood, 

 which, by the jxmclure of a needle, I drew from my finger. Where- 

 iil)on I faw, that the globules of blood from whence its rcdnefs pro- 

 ceeds, were, upon being thus diluted, more feparated and fcattered than 

 I remember to have ever obferved. Tliere was alfo tliis remarkable 

 appearance, that moft of the globules had a kind of finus or cavity 

 in them, the fame as if one had a bladder filled with water, and by 

 prefling a finger on the middle of the bladder, made a cavity or fur- 

 row in it. And, when the globules, after afluming a flat fliape 

 (for when they are fomewhat difperfed or feparated, their extreme 

 foftnefs caufes them to become flat) got fomewhat cloler together, 

 they put on an oval figure, and then, the cavities I have mentioned, 

 alfo became fomewhat oblong. But, when globules of blood are 

 concreted or coagulated, they exhibit the appearance of a folid body, 

 the component parts of which, cannot be difiinguilhed by the eye, ex- 

 cept that, in the coagulated parts, they feem rather to differ in fize. 



Now, having fo often experienced as I have done, how very foft 

 are the globules of blood, and how fpeedily, when flightly in con- 

 tadi and expofed to the air, they coagulate, I cannot, in any man- 

 ner, comprehend, how it is, that thofe globules when in the veins 

 and arteries, where they fo ftrongly propel and comprefs one an- 

 other, do not coagidate. Still lefs can 1 compreh.end, why, when 



