234 On the Differences in the Structure of Calculi. 



Jus-sien, on account of difficulties and imperfections un- 

 avoidable in so abstruse a study. No real friend to truth and 

 knowledge ever foments invidious rivalships in philosophy. 

 The field of science is now so vast, that its different cultiva- 

 tors find the advantage of dividing their tasks, and thus the 

 students of physiology, of natural systems, and of artificial 

 ones, may all powerfully assist ea:h other. Truth is pur- 

 sued by different paths, and nothing is more pleasing than 

 to see the various observers of Nature in a Society like ours, 

 mutually and harmoniously contributing, as we have all 

 alonjz; done, to enrich the scientific hive. I would therefore 

 conclude by recommending those who have leisure and op- 

 portunity for the purpose, to observe for themselves the ger- 

 mination of the principal families of plants, not only of such 

 genera as "are in dispute, but of all about which there can be 

 any doubt, most of which will easily be indicated by a com- 

 parison of Gsertner's work with the remarks in the fore- 

 going pages. 



XXXV. A Letter on. the Differences hi the Structure of 

 Calculi, which arise from their being formed in different 

 Parts of the urinary Passages; and on the Effects that 

 are produced upon them, ly the internal Use of solvent 

 Medicines, from Mr. William Brande to Everard 

 Home, Esq., F.R.S. 



[Concluded from p. 177.] 



Section VI. 



General Inferences. 



It appears from the preceding observations, that calculi 

 formed in the kidneys, and immediately voided, are almost 

 always composed of uric acid ; and that the phosphates are 

 very frequent ingredients in calculi of the bladder, more 

 especially in those which, from their situation, have been 

 exposed to a continual current of urine : they also uniformly 

 are deposited upon extraneous substances introduced into the 

 bladder, but appear never to form small kidney calculi. - 



In 



