IN NITRE BY THE AID OF ELECTRICITY. 
213 
Such at least are the results which can be obtained with calculi which have been 
long removed from the bladder and have been dried at 212°. The harder the calculi 
the greater the difficulty in dissolving them ; and as previous to their removal from 
the bladder they are far less hard than they are after they have become dry, and as 
calculi which are wet may perhaps allow of the passage of the electricity through 
their substance, instead of only through the surrounding solution, there is good reason 
to expect that there will be less chemical difficulty in dissolving them in the bladder 
than out of it. 
The skill which has been acquired in catching calculi in the bladder, the art of 
plating with platinum, the manufacture of vulcanized India rubber, will, with 
Mr. Weiss’s help, I hope, enable me to state at some future time what can be done 
in the body as well as out of it. Looking back now from the results that have been 
obtained, it appears as if they might have been foreseen. 
The uric acid and the phosphatic calculi are produced by the opposite states of 
over acidity and alkalescence occurring in the urine for a considerable time. By 
means of the galvanic battery acting on a saline solution, acid and alkali can be 
made to appear at any desired spot, in any quantity and for any time. Thus these 
opposite conditions may be produced on the surface of the stone at the spot, and 
only at the spot, where the action is wanted to correct the consequence of too much 
acidity or alkalescence ; whilst around the place of action an almost neutral solution 
will remain in contact with the bladder without causing irritation. 
I cannot conclude without stating what is due to MM. Prevost and Dumas. Their 
note is printed in the Annales de Chemie, voL xxiii. p. 202, 1823, Sur FEmploi de la 
Pile dans le traitment des Calculs de la Vessie*. 
In this note the mechanical action of the mixed gases (evolved from the decompo- 
sition of water) on a fusible calculus is stated to have been 12 grains in 12 hours; 
twenty-five pairs of plates being used and recharged each hour. 
The possibility of dissolving uric acid calculi is rejected, and no mention is made 
of caleuli consisting of oxalate of lime. 
In a postscript it is said that the addition of a ‘-certain quantity” of nitre gave, 
with phosphatic calculi, a better result than when water alone was used. 
M. Dumas appears afterwards to have occupied himself with experiments on the 
possibility of employing currents of electricity within the bladder of living animals, 
and not with the determination of the chemical action of substances evolved by the 
galvanic battery on the surface of different kinds of calculi. 
I am indebted to Dr. Du Bois Reymond for a reference to a paper, vol. i. p. 154, 
Oesterrichische Medicinischen Jahrbucher 1848, On the Effect of Galvanism on 
Urinary Calculi, by Dr. Ludwig Melicher of Vienna. He has employed the electric 
current for the electrolysis of the calculus itself, not for setting substances free which 
can act chemically upon it. He has made experiments on the living human body in 
two cases, it is said, with success. 
* See also Dr. Paris’s Pharmacologia, vol. i. p. 231. ed. 6. 
2 F 2 
