[ m ] 



XXIII. On the Discovery of Quinine and Quinidine in the Urine 

 of Patients under Medical treatment with the Salts of these 

 mixed Alkaloids, By W. Bird Hehapath, M.D.* 

 [With a Plate.] 



IT has long been a favourite subject of inquiry with the pro- 

 fessional man to trace the course of remedies in the system 

 of the patient under his care, and to know what has become of 

 the various substances which he might have administered during 

 the treatment of the disease. Whilst some of these remedies 

 have been proved to exert a chemical change upon the circulating 

 medium, and to add some of their elements to the blood for the 

 permanent benefit of the individual, others, on the contrary, 

 make but a temporary sojourn in the vessels of the body, circula- 

 ting with the blood for a longer or shorter period, but are eventu- 

 ally expelled and eliminated from it at different outlets and by 

 various glandular apparatus ; some of these substances are found 

 to be more or less altered in chemical composition in consequence 

 of having been subjected to the manifold processes of vital che- 

 mistry during their transit through the system, whilst others have 

 experienced no alteration in their constitution, but have resisted 

 all the destructive and converting powers of the animal labora- 

 tory, and by appropriate means have been again separated from 

 the various excretions by the physiological and pathological 

 chemist in their pristine state of purity. 



It has recently been somewhat more than a subject of conjec- 

 ture that, in common with several others of the vegetable alka- 

 loids, quinine may be included in this last class of remedial 

 agents, and several methods of discovering its presence have 

 emanated from different scientific observers. It has been re- 

 peatedly traced in the urine of patients suffering from intermit- 

 tent fever, to whom large doses of this substance have been ne- 

 cessarily administered. 



The nature of the tests hitherto employed and the various pro- 

 cesses adopted require large quantities of the fluid for examination, 

 and the imperfection of the evidence resulting from the experi- 

 ment still threw considerable doubt upon the value of the con- 

 clusions arrived at. It is merely necessary to allude to tannic 

 acid and tincture of iodine as the usual tests employed, both being 

 very far from efficient means of detecting minute quantities of 

 quinine in organic fluids. 



Having been struck with the facility of application and the 

 extreme delicacy of the reaction of polarized light, when going 

 through the series of experiments t upon the sulphate of iodo- 



* Communicated by the Author. 



t Papers published in Philosophical Magazine for March 1852, and 

 Analysis of Crystals in ditto for September 1852. 



