THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] 



JUNE 1854. 



LX. On a new and simple Method of determining the amount of 

 Urea in the Urinary Sea-etion. By Edmund W. Davy, A.B., 

 M.B.T.C.D., Lecturer on Chemistry in the Carmichael School 

 of Medicine, ^'c, Dublin*. 



UREA has long been regarded with much interest by scien- 

 tific men, on account of its physiological and chemical 

 relations. It represents one of the last stages of a series of me- 

 tamorphoses or changes which nitrogenous matter undergoes in 

 the animal ceconomy, and is the form under which the detritus 

 of pre-existing nitrogenous tissues which have become efiete, 

 principally pass from the system. This interesting organic base, 

 urea, is not only formed dm-ing the exercise of the vital functions 

 in man and some of the higher animals, but is also produced 

 during the chemical decomposition of a number of substances 

 containing nitrogen ; and the chemist can now obtain it in any 

 quantity by artificial means, and thus imitate one of the most 

 important results of the chemistry of life. 



In reference to medicine, m-ca is not without some practical 

 interest, as it is well known that during various diseased condi- 

 tions of the system the quantity of urea eliminated from the 

 blood by the action of the kidneys and excreted in the urine is 

 occasionally subject to great variation, and some ready means of 

 ascertaining its quantity in that secretion might frequently aid 

 the physician in forming his diagnosis of certain diseases. 



Different means of etfecting this object have from time to time 

 been proposed; but all the methods hitherto recommended, with 

 the exception, perhaps, of Baron Licbig's recent one, require for 



* Communicated by the Author. 

 Phil. May. S. 4. Vol. 7. No. 47. June 1854. 2 D 



