Rapid Estimation of Urea. 



151 



Estimation of Urea by direct Determination of the Nitrogen Gas 

 evolved by Sodic Hypobromite. 



The piece of appara- 

 tus now to be described 

 was exhibited at a meet- 

 ing of the Scientific 

 Club in 1871, and has 

 proved most useful for 

 the estimation of urea 

 by the hypobromite me- 

 thod, and, with a little 

 modification, for the 

 estimation of carbonic 

 acid in carbonates, and 

 for other similar pur- 

 poses. I shall only re- 

 fer at present to its use 

 in lire ome try. In this 

 apparatus the nitrogen 

 evolved is directly mea- 

 sured as gas under con- 

 ditions which admit of 

 very accurate determi- 

 nations of volume in 

 cubic centimetres. 



The apparatus is 

 shown in section in 

 fig. 2. The stand A 

 supports a tall glass 

 cylinder B. Through 

 the large india-rubber 

 cork which closes the 

 lower opening of the 

 cylinder the U-tube c 

 is passed, great care 

 being taken to avoid 

 breaking the small T- 

 connector c. The outer 

 limb of the U-tube is 

 provided with a glass 

 tapT. The limb within 

 the tall glass cylinder 

 is sufficiently wide to 

 contain 150 cub. cen- 

 tims. in the expanded 

 portion, which, in my 



