on the Effects of Magnesia. 21^ 



experiments have been made to ascertain what acids are best 

 calculated to produce the desired effect, or to illustrate their 

 mode of action. 



Since my former communication, I have lost no opportunity 

 of attending to this important subject, and hope that the con- 

 clusions, suggested by the following cases, will be deemed 

 satisfactory, and that their application in practice may lead to 

 useful results. 



Case 1. A gentleman, fifty years of age, who about ten 

 years before had undergone the operation for the stone,* was 

 attacked on the i4,th of January, 1810, with violent pain in 

 the right kidney and ureter, which lasted two days ; on the 

 17th, these symptoms subsided, and were followed by those 

 of stone in the bladder, which continued for some days, and 

 although he had taken abundance of barley water and similar 

 diluents, the stone shewed no disposition to pass. On account 

 of his former sufferings, this circumstance rendered him ex- 

 tremely uneasy, and on the evening of the 21st, he suffered 

 several severe paroxysms of pain on attempting to make water. 

 Under these circumstances, he was desired to take a purge, 

 composed of two ounces of infusion of senna, two drachms of 

 tincture of senna, and twenty grains of powdered jalap.-f In 

 three hours this began to take powerful effect, and during the 



• The ston- extracted consisted of a nucleus of uric acid about the size of a pea, 

 incrusted with a mixture of the phosphates. It was broken during the operation, 

 but appeared to have been of the size of a pigeon's egg. 



•f- I recommended this treatment in consequence of having heard SirEvFRARo 

 Home state a case^ in his Surgical Lectures, of a gentleman who suffered a bougie to 

 pass so far into the urethra, that it could not be removed by any instrument. During 

 the operation of a purge it was expelled with considerable force. 



MDCCCXIII. G g 



