30 On Gravelbj and Calculous Concretions. 



degrees, 13 grains to the ounce. Has the barytic, with all 

 its superior energy, less affinity for the uric acid than the 

 calcareous earth ? or does a superior affinity, to some other 

 ingredients of the urinary compound, supersede its union to 

 this ? 



I regret that the small quantity of stronthian lime water, 

 which I possessed, did not permit me to extend my inquiries 

 with it. 



Finding, then, that our alkaline earth of lime, in the 

 •weakest possible state of solution, and in the smallest pro- 

 portion, eflcctually prevents the crystallization, or keeps in 

 solution the lithic acid of urine : if we only suppose that 

 it reaches the kidneys and bladder in the smallest quantity, 

 it must produce similar effects there, obviate the further 

 formation of gravelly matter, or further accumulation of 

 pre-existing calculous concretions of this kind. 



Let us now proceed to inquire into the effects of the pure 

 and carbonated alkalies themselves. The action of the former 

 being well known and acknowledged, I shall content myself 

 with one experiment, and pass on to the latter. 



Experiment VII. 

 To four ounces of the urine of a child often depositing 

 gravel, on cooling, were added ten drops of the aqua kali 

 puri of the shops. After seven days no sign of separation: 

 some observable in the standard after some hours. 



Experiment VIII. 

 To four ounces of urine were added three grains only of 

 crystallized carbonate of potash, the purity of which was 

 ascertained by Dr. Perceval and myself, and containing, 

 according to Mr. Kirwan, 1-23 grains of alkali. After se- 

 veral days no appearance of crystallized matter : some in 

 the standard after forty-eight hours. 



Experiment IX. 



To the same quantity of urine were added two grains only 

 of the same, with the like result. 



From the pure and carbonated, let us now proceed to the 

 ftuper-carbonated and sub-carbonated states. 

 , . i Experiment 



