OF THE BLOOD. 231 



The effects of acids are very different. I have tried the 

 vitriolic, nitrous, muriatic, distilled vinegar, and the acid of 

 phosphorus ; these, when much diluted, have the same effect 

 as water in making the vesicle spherical, and in proportion as 

 they are less diluted, they dissolve the vesicles, without making 

 them spherical as water does. I never could find any point 

 of dilution where the acids, like the neutral salts, produced 

 no change on the figure of the vesicles. This experiment is , 

 the more to be attended to, as these vesicles have been supposed 

 to be oily and saponaceous, which is improbable, since they 

 dissolve *more readily in acids than in alkalies. 



Salts made with earth of alum, and any of the acids, always 

 corrugate those vesicles unless they be much diluted, when 

 their effects are similar to water alone ; that is, they make 

 the vesicle assume a spherical shape. I could not discover 

 any point of strength in these solutions, where the particles 

 would remain in them without being changed in their shape. 



The same was observed of spirits of wine ; some of the me- 

 talline salts, as copperas, sublimate and Roman vitriol, were 

 tried, and when much diluted their effects were not different 

 from those of water ; but in proportion as the solution was 

 stronger, they corrugated the vesicles more and more. 



Urine, when containing much of its salts, has effects similar 

 to the serum, but in proportion as it is weaker, its effects are 

 more like those of water. 



The use therefore of those salts which enter into the com- 

 position of the blood is probably to preserve the red vesicles 

 in their flat form (cxin), for we must suppose some advantages 

 attend that shape, since nature has made use of it so generally 



puscles is mentioned in Notes xciv and cxi ; and the different action of 

 alkalies and neutral salts on the red blood-corpuscles and pale primary 

 cells, in Note cxxn, p. 254. The modem names of some of the salts 

 mentioned in the preceding page of the text, are given in the Note 

 at page 12. Mr. Ancell a has given a copious table of the effects of 

 various substances on the red corpuscles. 



(cxin.) The effect of the salt of the serum is doubtless, as Hewsoii 

 discovered, to preserve the flat shape of the blood-corpuscles. The 

 salt also tends to keep them asunder, preventing that increased aggre- 

 gation of them which takes place in buffy blood ; and this may be a 

 cause of the well-known efficacy of salts in inflammation : see Note xxm. 



a Lectures on the Blood, Lancet, 1839-40, i, 522. 



