440 



Dr. W. J. Russell and S. West. 



[May 27, 



without raising the temperature to such a point that chloride of 

 sodium would be volatilised. The weight, however, of carbon remain- 

 ing in these cases was exceedingly small. The amount of chlorine in 

 the urine was ascertained by dissolving this residue in water, and 

 adding a standard solution of silver nitrate. 



Obviously, these latter determinations are not of the same degree of 

 accuracy as are those of the nitrogen. Still they strikingly point out 

 the variations in the composition of these urines, and give important 

 comparable results. 



The first series (Table I), consisting of twenty-three observations, 

 falls into several small groups. The relation of the urea-nitrogen to 

 the total nitrogen was, in all cases, calculated out in percentage 

 amounts (the total nitrogen being taken as 100), and the mean of 

 each group of observations given. 



The first group (Table II) consists of six cases of pneumonia, and 

 in these the urea-nitrogen represents 90 per cent, of the total nitrogen.* 



The second, of two cases of jaundice, with two determinations in 

 each. The mean of the first giving 85 "7 per cent. ; of the second, 90*2 

 per cent. 



The third, of two cases of albuminuria, in which the mean is 86 per 

 cent. In these observations, the albumen was previously precipitated 

 and removed. In a third case the determination was made without pre- 

 viously removing the albumen. In this latter, the percentage was 63'6. 



The fourth group consists of a collection of cases of various kinds. 

 One of pyeemia, one of typhoid fever, rheumatic fever, acute dysentery, 

 pleurisy, hepatic abscess, and lencocythsemia, two of erysipelas, and 

 two of diabetes, making eleven in all. The mean percentage of them 

 all is 93-8. 



The lowest percentage in this first series is found in the cases of 

 albuminuria, and of jaundice, a fact of interest as bearing upon the 

 place of production of urea. 



The second series consists of eighteen determinations made upon 

 three cases, in which the diet was fixed, and the patient in a condition 

 of absolute rest (cf. Table III). 



These give a mean of 90T per cent. The mean of all the cases in 

 the two series is 89'3, or, if the cases of albuminuria and jaundice be 

 excluded, 91'3 per cent., and this agrees almost exactly with the 

 results of Professor Parkes' experiments, in which the mean arrived 

 at is 91 per cent. 



If a calculation be made from the tables given in books of the 

 amounts of the urinary constituents in a normal urine, the urea is found 

 to represent about 96 per cent, of the total nitrogen, or if allowance 



* It is worthy of note that in none of these cases is the percentage of urea high ; 

 a fact to which attention has "been drawn in a preTions paper. " Med.-Chir. Soc. 

 Trans.," vol. lviii. 



