Chimka! Eiiqiiiriei into th,- Nature of the Riihets. ITj 



With regard to the urine of rachitic fubjecls, the moft remarkable fafts are, i. The 

 abundantand apparently earthy fediinent it depofits (fpontaneoully) is different from that 

 of old rhcn, by its colour, which is grey and does not refemble phofphate of lime, and alfo by 

 its much greater quantity. For a pound of this urine let fall two gros, whereas the fame 

 quantity of the urine of old men depofited only 45 grains. 



2. The extract left by evaporation is likewife much more confidera'ole than in other urine. 

 It is one third more in quantity than the extraQ afforded even by the urine of aged perfonS. 



From thefe two firfl obfervations it follows, that the folids in rachitic fubje£ls are deRroyed 

 with much more rapidity than even in old men ; and that they afford a much more abun- 

 dant portion of wafte to the urine. 



3. The light depofition occafioned by lime water in the uiine of rachitic fubje£ls is 

 very fmall in quantity, brown, gelatinous when frefh, and pulverulent when dry. It does 

 not at all refemble calcareous phofphate. 



4. The depofition formed by the folution of mercurial nitrate is not abundant, neither of 

 a rofe colour as in the urine of adults, nor grey like that of old men. It is always white, 

 and confequently has no external refemblance to the phofphate of mercury. The author 

 affirms that it refembles a mercurial oxalate. 



Laftly, the urine of the fame rachitic fubje£ts when cured, exhibits again all the charac- 

 ters obferved in the urine of healthy children. 



We {hall not add to the reflexions of the author. In effefl, though thefe firft obferva- 

 tions are curious, they are incomplete. We offer them to phyficians fimply as the ele- 

 ments of an inveftigation which it is of importance to continue and bring to perfeclion. 

 We (hall therefore proceed to the curative and experimental parts of the memoir. 



We muft remark, however, in this place, that the author prefents in his work a judicious 

 and methodical expofition of the whole treatment of the rachitis by other phyficians ; that 

 he eftimates the value of each remedy, and every part of the treatment, from the circum- 

 ftances to which they are applicable, the degrees of the malady in which they are to be ad- 

 mitted, and the indications they anfwer. Setting afide, therefore, every thing which is not 

 peculiarly his own, we (hall in this place attend only to that which relates to the ufe and 

 effefls of calcareous phofphate and alkaline lotions. 



One of the fails which it was of the utmofl importance to eflablllh, was the tranfition of 

 the calcareous phofphate from the inteftinal paffjges, into thofe of circulation and fecretion. 

 Fourcroy had already well afcertained that the ferum of milk contains this fait naturally. 

 Vauquelin had proved its cxiftence, as well as that of pure foda, in the feminal fluid; but 

 was it poffible that it could pafs unaltered from the ftomach and inteftines into ihe veflels 

 which contain the blood and lymph ? Could it by this means apply itfelf to the bones .' 

 This was to be afcertained by experiments. 



[To he continued.^ 



XI. 



On the Nature of the Diamond. By Sm/TJ/SON TenNANT, Efq. F. R. S. * 



O I R Ifaac Newton having obferved that inflammable bodies had a greater refrailion In 

 proportion to their dcnfity than other bodies, and that the diamond rcfcmbled them in this 



• rhJLI^i^liicjl Tranfaflions, 1797, p. 123. 



Vol. I. — Ji;lt 1797. A a property, 



