2 go SCIENCE PROGRESS. 



later the abdomen was reopened, and the loop emptied of 

 all remaining contents, which were analysed. 



I will here quote one or two of the experiments as 

 examples of the method employed and the results obtained. 



(i) Dog 14*1 kilos. Blood serum : A = 0*634 : NaCl = 

 0*620 per cent. Introduced 120 c.c. of salt solution con- 

 taining o'3 per cent. NaCl, and therefore '36 grams NaCl 

 (A = cv2 3o). Fifteen minutes later the loop only contained 

 18 c.c. fluid, with 6 per cent. NaCl (i.e., o'io8 grams). 



(2) Dog 7 kilos. Blood serum : A = "642. 



(a) At 9h. 6m. injected 80 ccm. NaCl 1 "98% = l '5& g r - NaCl. 

 At 9I1. 26m. found 80 ccm. ,, 1 '20% = 0^96 ,, 



Absorbed in 20 mins. o ccm. '62 gr. NaCl. 



(b) At 9I1. 30m. injected 80 ccm. NaCl 1 '98% = 1 '58 gr. NaCl. 

 At 1 oh. 10m. found 63 ccm. ,, i'io7 =0*69 „ 



Absorbed in 40 mins. 17 ccm. containing C89 gr. NaCl. 



(c) At 1 oh. 1 3m. injected 80 ccm. NaCl 1 "98% = 1 '58 gr. NaCl. 

 At iih. 13m found 42 ccm. ,, o'967 = o'40 ,, „ 



Absorbed in 60 mins. 38 ccm. containing n8gr. NaCl. 



The freezing points of the solutions were : — 



Of the 1 '98 per cent, solution A = K243. 



And of the unabsorbed fluid in (a) A = o - 9i6. 



(6) A = 0-802. 

 (c) A = 0790. 

 It is evident, simply from these two experiments, that 

 the absorption of water and salts from the intestines cannot 

 be due to the osmotic differences between blood and 

 intestinal contents. 



In experiment (1) the osmotic differences would give 

 rise to a transfer of water from intestines to blood, and of 

 NaCl from blood to intestines. We find, however, that 

 there is an absorption both of water and of salt. 1 



In experiment (2) the osmotic difference would occasion 

 a flow of water from blood to intestines, and of salt from 

 intestines into the blood stream. Here again, however, 



1 For a possible mechanical explanation of this result, see Journ. of 

 Phys., vol. xviii., p. 113. 



