269 



Oxalate of lime calculi were then tried. 



Experi- Duration of Power of 



ments. experiment. Strength and temperature of solution. Battery. Result, 



h m o grs. 



1. 7 i nitre, I water 90 ... 5 ... 0| dissolved. 



2. 7 „ „ 104 ... 10 ... 2 



3. 6 15 In sulphate of soda 101 ... 10 ... 2 



4. 5 45 In common salt 102 ... 10 ... I 



5. 6 10 i nitre, f water 108 ... 20 ... 6 



^' ^ 1^ {^Toda'^'^^.!'^?.!^^^'''.^!}"^ - 2^ - 1 dissolved. 



7 3 15 / 1 nitre with bichromate of 1 J I -j^ 2o 2 



\ potash J 



8. 3 17 i nitre 110 ... 20 ... 2^ 



9. 2 50 i nitre 92 ... 20 ... 2^ 



10. 3 „ 100 ... 40 ... 5 



Hence oxalate of lime calculi can be only very slowly dissolved in 

 a solution of nitrate of potash, which acts far more energetically on 

 uric acid calculi. The action is at least four times greater on uric 

 acid calculi. Oxalates with urates, and oxalates with phosphates, 

 were found to be far more rapidly acted on than oxalate of lime alone. 



Phosphatic calculi were then taken. A piece of hard phosphate of 

 lime gave 



Duration of Strength and tempera- Power of 



Experiments. experiment. ture of solution. battery. Result. 



h m grs. 



1 7^ i nitre, f water 102 ... 10 pair ... 15 



2. with fusible calculus 1 13 „ „ 96 ... 20 ... 31 

 The action was chiefly at the positive electrode. 



Experiments with marble. 



1 5i i nitre 104 ... 10 ... 27i 



.,. 6i {^Vdi^'^'!'.*"^}^^! - - 



From these experiments the following conclusions are drawn: — 

 From two to nine grains of uric acid calculus can be dissolved in an 

 hour in a neutral dilute solution of nitre at the temperature of the 

 body, whilst in the same time from two to twenty- five grains of 

 phosphatic calculus can be dissolved. However, only from half a 

 grain to two grains of oxalate of lime can be removed by the same 

 means in the same time. Still, if the stone consists of oxalate with 

 urate, from one to two grains maj^ be dissolved in an hour ; and if it 

 consists of oxalate with phosphate, from four and a half to five and a 

 half grains can be taken away in that time. 



These results may be obtained with calculi which have been long 

 removed from the bladder, and have been dried at 212°. 



MM. Prevost and Dumas in 1823 proposed to treat calculi by the 

 galvanic pile. By means of the mechanical action of the mixed gases 

 evolved by decomposing water, they found that phosphatic calculi 

 might be disintegrated. The chemical action of the substances 

 evolved by galvanic action on the surface of calculi was not deter- 

 mined by them. 



The Society then adjourned over the Christmas vacation to the 

 6th of January, 1853. 



2. 



Proceedings of the PvOyal Society. Vol. VI. No, 94. 19 



