120 Journal of the Asiatic Society of Bengal. [N.S., XVIII, 
ing together all the nitrogen strengths of the urine samples of 
the two kidneys respectively, the average strengths were in 
the ratio of 07: 1) than the urine of the normal kidney. 
The fact that the quantity ratio of 1:4: 1 was identical with the 
nitrogen strength ratio inverted (1:4: 1 = 1: 0°7) was doubtless 
a coincidence, but it proves that on the whole the amounts of 
total nitrogen excreted by the ligatured and “‘ normal’ kidney 
respectively were equal (the ligatured kidneys excreted a total 
of 0:033474 gm. and the ‘“‘ normal ”’ kidneys a total of 0°033750 
gm.). In other words, the ligaturing of the renal afferent vein 
in each of these frogs makes practically no difference to the total 
amount of nitrogenous matter which these ligatured kidneys 
excrete as compared with the ‘‘ normai’’ kidneys, despite the fact 
that the ligatured kidneys are, on the current view, deprived of 
three-quarters of their total blood-supply by the ligaturing oj the 
renal afferent veins. These results, obtained in 15 out of 18 ex- 
periments must be regarded as the normal results, and the 
three abnormal results must be regarded as having been due to 
the preponderance of a particular factor, such as, e.g. the well- 
known alternation of activity of the kidneys (e.g. at the 
commencement of the experiment when secretion is most 
vigorous the ‘‘normal”’ kidney may have been at the “ flood 
tide” of its activity and, if the experiment was brief, may 
have therefore secreted more than the ligatured kidney for 
this reason) or extra active absorption of water by the belly skin 
(the influence of which will be appreciated when I have ex- 
plained the cause of the normal results). 
Further Experiments to Determine the Amounts and Chloride 
(as NaCl) Strengths of the Samples of Urine. 
Twenty-three experiments were attempted altogether (simi- 
lar to those already described save that the urine was estimat- 
ed for chloride by Dr. A. P. Sirear, instead of for total 
nitrogen), of which fourteen were successful. Out of these 
fourteen experiments, ten gave as their result that the urine 
of the ligatured kidneys was greater in amount (the total amount 
of urine secreted by the ligatured kidneys=18°15 c.c. and 
that by the “ normal ” kidneys= 10°65 c.c., the ratio therefore 
being 17 : 1) and contains a lower percentage of chloride as com- 
was obtained : in all the four experiments with abnormal 
results, water was in the dish beg 
The normal results confirm me in my denial that the results 
obtained by Bainbridge, Collins and Menzies (see Part IJ, p. 
are true. It will be remembered that these authors maintain 
that, with a venous supply, the kidney secretes urine weaker in 
