238 



" fiiisse, in linteis sanorum infantum utina madidis, co- 

 " piani sabuli nephritici, satis duri, quod videtur una cum 

 " urina excretum fuisse. Cum enim magna cura habere- 

 " tur, ne hi infantes, (illustri genere nati,) diutius urin^, 

 " vel aliis sordibus, conspurcati manerent, et urina statim 

 " per lintea penetret, vix videtur possibile fuisse, ut in 

 " urina jam emissa hoc sabulum productum fuerit, intra 

 " unam alteramve horm." 



And, again, he adds, " Hoc sabulum, in urina etiaiii 

 " sanissima concrescens, vocari posset calculus nativus; 

 " a quo nemo liber est; at qui tunc tantum metuendus 

 " videtur, si cito in urina concrescat. Felices illi, in qui- 

 " bus tardissime hoc fit. Propriam saepius examinavi uri- 

 " nam, laetusque vidi, rudimenta ilia prima caculi sepa- 

 " rari quam tardissime, requiri quandoque horas viginti 

 " quatuor et ultra, antequam in sabulum majoris molis 

 " concrescere potuerint. Sed et, licet decimum tertium 

 " setatis lustrum emensus jam fuerim, ab omni lithiasi 

 " immunis vixi." 



The mode and appearances, attending the separation 

 and crystallization of this substance, from healthy urine, 

 is one of the most beautiful, that, probably, chemistry 

 affords. But, as the circumstances are so minutely and 

 correctly detailed by Boerhaave, and his conmientator. Van 

 Swieten, in his treatise De Calculo, Vol. V. page 201 and 

 202, and correspond so much with my own experiments, 

 so often repeated; I must refer to him. On this passage, 

 however, I must observe, that the space of twenty-four 



hours, 



