266 



it turns witk litmus, and, sometimes, but feebly, Avitli this 

 most . delicate of all acid tests. A single drop of phos- 

 phoric acid was added to one ounce of distilled water. Of 

 this Aveak acid impregnation, one drop Avas sutficient to 

 turn the infusion of iitmvis of as clear a red as the mine- 

 ral acids do; whilst seven of urine manifested but very 

 weak effects of acidity, and required some time to shew 

 any. If the urine, therefore, does not exceed its natural 

 standard of acidity, we have nothing to apprehend. And 

 here, indeed, we must again admire the wonderful wisdom 

 of Providence. The occasion (may I be allowed to say so, 

 and that, too, before so competent an assembly?) required 

 some chemical discrimination. It Avas necessary to care- 

 fully provide for the expulsion of the recrementitious part 

 of the osseous fabric (Avhich is very considerable) out of the 

 system: but as this salt is insoluble in an aqueous vehicle, 

 such as the urine, nothing more Avould be necessary, to ob- 

 viate this difficulty, than a certain degree of super-satura- 

 tion, or state of acidule, Avhich Avould more effectually pro- 

 vide for its solubility, and its elimination. But by going 

 thus far, Avhilst it attended to one excretion only, it Avould 

 have entirely forsaken its charge of another, committed also 

 to this fluid; and, by this degree of super-saturation, pre- 

 cipitate, retain in the system the uric acid, and occasion 

 as frequent an occurrence of gravell}^ and calculus com- 

 plaints, amongst mankind in general, as noAv occurs among 

 the gouty. It, therefore, prudently formed that degree only 

 of acidulous phosphat of lime, Avhich, though insoluble out 



of 



