296 On Gravelly and Calculous Concretions. 



ties, I never could procure the separation or transition of a 

 single bubble of carbonic acid into a jar of lime water. 

 And if this weak acid reaches the kidneys nndecom posed 

 or uncombincd,\ve shall have less difficulty in believing the 

 more powerful ones may do so. That the tartarous acid in 

 the combination of tlie acidulous tartarite of potash exerts 

 powerful effects on the functions of the kidneys, is well 

 known ; and that the urine is at the same time rendered 

 more acid, T have repeatedlv ascertained bv the usual tests. 

 We may say the same of the other vegetable acids, which 

 manifest also diuretic power;-, awd increase the natural 

 acidity of the urine. Linnaius, in his second volume of 

 the Jlmcenitates Academic ce. Da Genesi Calculi, already 

 quoted, mentions his having made the following experi- 

 ment to this ])urj)ose. He says : " Hisce dicbus ipse ex- 

 perimentum instil ui cum urlna; hsc communitcr a solu- 

 tione lacmus parum adm'-'dum rufescit; at si libram unam 

 vel alteram vini Rhenani, vel alterius vini acidi hauserim, 

 post horam unam vel pluves, valde rubra et rutilans evadit 

 urina, ab affusa solutione lacmus; certo indicio, acidum 

 vini totum corpus permeasse, et urinam infeoisse." Nor 

 should we wonder that tlicse energetic substances should 

 pass unaltered to the kidneys, when we find so many mild 

 vegetable matters do so. I will not mention the commu- 

 nication of so volatile a principle as odour, but will more 

 particularly dwell on that of colour. Rhubarb, turmeric, 

 madder, and many other substances, so completely imparl, 

 their colour to urine, that they v.ould appear to be very 

 little altered. Nav, the juice of the beta vulgaris, a mild 

 esculent of the pentandrous class, so deeply reddens it as 

 to cause it to be mistaken for bloody urine, of which ^^ 

 late instance has occurred in my practice. 



As to alkaline substance?, it has been at all times known 

 that thty connnunicate their properties to this excremen- 

 titious liquor. A perseverance in the use of the aqua kali 

 puri of the shops for a few days, even in small doses, con- 

 verts its ace^^cent into the alkaline state ; and we have every 

 reason to suppose that ihe same takes place with the car- 

 bonates, which are taken in so much larger quantities, 

 7"his seems confirmed by experiments made ui London and 

 Paris; and the alkalescent impregnation of the urine was 

 ascertained by the formation and precipitation of the acidu- 

 lous tartarite of potash upon the addition of the tartarous 

 acid* Yet, from a good deal of experience in these matters, 

 I H)ay aver, that as to the carbonates the dose must be con- 

 siderable, (which was the case in London,) and continued 



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