230 RED PARTICLES 



The neutral salts which, when diluted with water, have been 

 observed to have the effects above described, are Glauber's salt, 

 Epsom salt, a salt formed of the volatile alkali and the vitriolic 

 acid, common nitre, cubic nitre, a salt made with the volatile alkali 

 and the nitrous acid, as well as the salts made with the nitrous 

 acid and magnesia, or with the nitrous acid and chalk, and also 

 common salt, digestive salt of Sylvius, and a salt made with 

 vinegar and the fossil alkali. These experiments were sufficient 

 to- convince me, that this property was very general among those 

 salts which consist of acid and alkali, and therefore it seemed 

 unnecessary to prosecute this inquiry further. 1 But acids and 

 alkalies have different effects on these vesicles from what neutral 

 salts have. 



The fixed vegetable alkali and the volatile alkali were tried 

 in a pretty strong solution, and found to corrugate the vesi- 

 cles, and in proportion as they were diluted, their effects be- 

 came similar to water alone; but it is not easy to find the 

 point of strength where the vesicles would remain unaltered in 

 the solution. And here we may observe, that since these ve- 

 sicles are found to dissolve so readily in water, and not to be 

 dissolved in these solutions of alkali, it is a strong argument 

 against their being oily or saponaceous, as they have been 

 suspected (cxn). 



1 These experiments were made by putting one drop of the saturated solution of 

 the salt into a teacup, and then adding distilled water by a few drops at a time, 

 and to this mixture the serum of the blood highly tinged with the red vesicles was 

 added. 



triangular, or irregular depressions on the surface ; in the centre of others, 

 an appearance is presented as of a granular nucleus ; many become 

 mulberry-shaped. All these changes may be occasionally seen in pure 

 blood, as noticed in Note cii, p. 223, and in the Appendix to Gerber's 

 'Anatomy,' p. 9. Urine, when rather strong, produces the same 

 changes ; though in certain states it has so little effect on the corpuscles, 

 that it may be used for diluting the blood to observe their shape. 



(cxn.) That the corpuscles are not oily or saponaceous globules, 

 requires no proof : see Note cvm. But I have always found that they 

 disappear, as if dissolved, when treated with liquid ammonia or potash. 

 Senac a remarks that the corpuscles, according to Leeuwenhoek, are 

 dissolved by volatile salts. The effect of water and of salts on the cor- 



il Traite du Coeur, torn. ii. p. 135, ed. 1749. 



