Xll 



Urine in Health and Disease.' In his preface the author says " the 

 increased desire for more intimate acquaintance with animal chemistry, 

 which has lately been evinced by the medical profession, induces me 

 to present this little work to public notice. The more philosophical 

 modes of investigation at present adopted to ascertain the diseased 

 conditions of the living system, have found a new branch of inquiry 

 deserving the attention of the student." He then describes his 

 method of separating the various ingredients of the blood, and as 

 regards his discovery of urea he evaporated the blood to dryness and 

 treated the residue with ether. He also made an exhaustive analysis 

 of the urine, showing that the colouring-matter was a distinct principle, 

 and gave the various tests for albumen. Bright had already observed 

 that the phosphates were precipitated by heat, and thus was some- 

 times a cause of error in testing for albumen. He referred to Rees 

 for an explanation, who, after a series of experiments, determined 

 that it was muriate of ammonia which kept the phosphates in solu- 

 tion, and that it was the decomposition of this which thus necessarily 

 caused their precipitation. For the presence of sugar he did not use 

 chemical tests, but evaporated the urine and dissolved out by alcohol. 

 In a paper published in 1838 in the ' Guy's Hospital Reports,' Rees 

 showed how sugar could be obtained from diabetic blood, as its pre- 

 sence therein had been previously doubted. He evaporated the 

 blood, soaked the residue in water, treated with ether to remove urea 

 and fat, and then allowed the remainder to crystallise. 



In the year 1841 Rees made, in conjunction with Mr. Samuel Lane, 

 some very important observations on the corpuscle of the blood. 

 They concluded that it was a flattened capsule containing a coloured 

 fluid, and they further showed the changes which it underwent on 

 the application of reagents as saline fluids and syrup. They inferred 

 from this that in the living body there must be a similar osmotic 

 change going on, as in anaemia and in cases where the saline sub- 

 stances were in excess. Rees subsequently made observations on the 

 nucleus of the corpuscle in different animals, and showed the simi- 

 larity of the white corpuscle to that of lymph and pus. Although 

 finding urea in various secretions in cases of diseases of the kidney, 

 yet often failing to discover it in the blood, he doubted whether its 

 presence was the cause of convulsions and other nervous symptoms so 

 frequently met with in Morbus Brightii. 



He communicated two papers to the Royal Society — one in 1842 

 entitled " On the Chemical Analysis of the Contents of the Thoracic 

 Duct in the Human Subject." The fluid was obtained from a 

 criminal executed at Newgate, and taken an hour after death. An 

 article on chyle and milk, written afterwards, is to be found in Todd 

 and Bowman's ' Cyclopaedia of Anatomy and Physiology.' His other 

 paper presented to the Royal Society was entitled " On the Formation 



