GOUTY CONCRETIONS. 477 



Organic matter . . . 7'292 



Phosphate of lime . . 63-636 



Phosphate of magnesia . . 10-909 



Carbonate of lime . . . 18-181 ] 



Gouty concretions, which frequently form on the joints of 

 the hands and feet, consist of urate of soda, with a little of the 

 urates of potash and lime, chloride of sodium, and ordinary 

 animal matter. Wollaston was the first to describe their com- 

 position correctly. The two following analyses will illustrate 

 their composition : 



Laugier. 1 Wurzer. 



Uric acid . . . 16-7 20-0 



Soda .... 16-7 20-0 



Lime . . . .8-3 10-0 



Chloride of sodium . .16-7 18-0 



Chloride of potassium . . 2-2 



Animal matter . . . 167 19'5 



Water . . .8-3 10-3 



Some gouty concretions, about the size of a pea, were ana- 

 lysed by Pauquy and Bor, and found to consist of urate of 

 soda, urate of lime, and an albuminous substance, but no 

 chlorides. 



[In page 408 there is an analysis of bone in a case of arthritis, 

 by Marchand. The same chemist analysed a gouty concretion 

 on the lower articulation of the femur. It contained : 



Urate of soda . . . 34-20 



Urate of lime . . . 2'12 



Carbonate of ammonia . . 7 '8 6 



Chloride of sodium . . . 14-12 



Water . . 6-80 



Animal matter . . . 32-53 



Lehmann analysed a tophaceous concretion that formed on 

 the metacarpus of a man only 22 years old, but who had suf- 

 fered from well-marked gout. It was, on its removal, soft 

 and tough, white internally, and reddish-brown on its external 

 surface. When dried, it formed a white chalky mass. Under 

 the microscope there were seen innumerable foursided prisms 



1 The loss in this analysis amounts to 16-6. 



