Natural History. 187 



night and morning, when the calculus had become so friable, as to 

 oblige the discontinuance of the experiment. It had lost in weight 

 like the former calculus. After some days' rest, the dog was killed, 

 and the bladder examined; its texture was just as usual, its appear- 

 ance presented nothing particular, and when opened for the evacua- 

 tion of the urine, its fibres contracted just as usual. 



The innocuous nature of such a voltaic current on an organ, at a 

 certain distance from it, may be readily ascertained in the following 

 manner : place the conductors and calculus in the water, as in the 

 first experiment, then pass the current, and also dip the tongue into 

 the water; it will be found that whilst the calculus is undergoing 

 rapid decomposition, the tongue, sensible as it is to the influence of 

 electricity, will scarcely be able to ascertain its presence, when not 

 more than 15 or 18 lines from the calculus. 



It is evident that this process will be of no avail in the treatment 

 of calculi, composed of, or containing much, uric acid ; and MM. 

 Prevost and Dumas do not think of recommending the process in 

 cases even where it promises help, until farther investigation has les- 

 sened the difficulties, and illustrated the points which remain untried. 

 They have introduced calculi into the bladders of dogs; and when 

 the wounds have cured, propose practising on them, that the best 

 method for the human being may be ascertained. It will be re- 

 quisite to ascertain, by experiment, what fluid will be best for the 

 distension of the bladder; and it is indispensable to find means 

 of ascertaining accurately the nature of the calculus whilst in the 

 bladder. They are encouraged against these and other difficulties, 

 however, by having already ascertained, at the Jardin des Plantes, 

 that the action of the pile causes no bad effects on the bladder ; 

 and also that the addition of a certain quantity of nitrate of pot- 

 ash to the fluid for injection, renders the decomposition more rapid 

 and sure, so that the hard and compact phosphates give way in 

 an analogous manner to those that are porous. — Ann. de Chim. 

 xxiii. 202. 



1 5. Dumbness cured by Electricity, by Miles Partington, esq. — The 

 following account of a galvanic experiment on a dumb boy having 

 been inserted in several newspapers, unknown to me at the time, 

 I am induced, by the advice of several medical friends, to attest the 

 truth and correctness of the detail, as far as respects my knowledge 

 of the circumstances attending the event of his recovery ; and 

 having made the strictest inquiry of those immediately connected 

 with Christ's Hospital, I have every reason to believe the following 

 detail to be strictly true. 



Eighth months ago, a youth about twelve years of age, named 

 Oldham, in Christ's Hospital, went to bed at the usual hour, and in 

 the morning rose totally dumb. He preserved every other faculty, 

 but was obliged to write on a slate for every thing that he wanted, 

 that he could not explain by signs, Every means of internal re- 



