303 



estimation, can never have taken place beneath the present rectilinear 

 and parallel strata. 



Dr. Richardson assumes as a fact, that strata having very strong 

 resemblance were once continuous, however interrupted we now find 

 them ; for instance, the stratified remnants at the tops of the Seafin 

 and Slievegallon, between which the valley of the Mayola is an ex- 

 cavation 1700 feet deep and three miles wide, were originally con- 

 nected in their present position by similar materials, the whole of 

 which have been completely carried away. And again, to the north- 

 ward, between Seafin and Carntogher, the same stupendous operations 

 have carried away the parts which formerly connected these undis- 

 turbed remains of the same strata. 



The number of basaltic hummocks thus left on the tops of various 

 mountains, is represented to be considerable, as if they had been left 

 by the unknown sculptor for the express purpose of showing how high 

 the original surface of the country formerly reached, a conclusion 

 which appears formidable ; but the author does not admit that any- 

 thing is absurd, incredible, or impossible, in geology and cosmogony. 



A Letter on the Differences in 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, by the internal Use 

 of solvent Medicines, from Mr. William Brande to Everard Home, 

 Esq. F.R.S. Read May 19, 1808. [PhiL Trans. 1808, p. 223.] 



Mr. Brande's observations were made during an examination of 

 the calculi contained in the Hunterian Museum, and of some also in 

 the possession of Mr. Home. 



Three calculi, formed in the kidneys, were examined. One con- 

 sisted of uric acid, nearly pure ; another, weighing seven grains, con- 

 tained 4^ uric acid, and 2^ animal matter. A third consisted of 

 oxalate of lime ; and it is added that a fine powder is also voided 

 from the kidneys, consisting of the ammoniacal phosphate of mag- 

 nesia, and of phosphate of lime. 



Calculi retained in the infundibula, or pelvis of the kidneys, may 

 be increased either by a deposition of uric acid, or may be coated by 

 an external lamina, consisting of the phosphates. 



Calculi met with in the bladder, are of four kinds. 



1 . Formed on nuclei of uric acid, from the Iddneys. 



2. On nuclei of oxalate of lime, from the kidneys. 



3. Formed on sand or mucus deposited in the bladder. 



4. Formed on extraneous bodies introduced into the bladder. 

 Those consisting of uric acid vary in colour, from a deep reddish 



brown to a pale yellowish brown. Those containing phosphate of 

 lime, and the triple phosphate of magnesia, are whiter, and are often 

 soft and friable. Those which contain oxalate of lime, called mul- 

 berry calculi, are browner, harder, and less soluble. 



Out of 150 examined by Mr. Brande, 



16 were composed of uric acid. 



