SYNTHESIS OF THE PRODUCTS OF DIGESTION 59 



blood in unsplit state. Folin found on resorption of glyco- 

 coll or alanin from the stomach or large intestine an increase 

 in the residual nitrogen, usually too of the urea, in the 

 blood. 32 



There is another series of observations which are at 

 least not contradictory to the supposition that the amino- 

 acids pass into the blood. Pringle and Cramer 3S found the 

 blood of a digesting animal to contain a somewhat higher 

 residual nitrogen than that of a fasting animal. Embden 

 and his pupils have been able to detect the presence of small 

 quantities of aminoacids in the blood and their passage 

 into the urine by means of the naphthalin-sulphochloride 

 method. 34 In pathological states the aminoacids in the 

 blood can doubtless be increased. According to Neuberg 

 and Eichter 35 in acute yellow atrophy of the liver amino- 

 acids may be found in such quantities as to suggest that 

 perhaps in some way owing to the loss of hepatic function 

 a further change of the catabolic products of proteids (split 

 in the intestine into crystallizable products) fails to take 

 place. In uraemia, too, at times the aminoacids are appar- 

 ently increased in the blood. 



Moreover it should not be overlooked that 0. Cohnheim 36 

 in his studies upon invertebrates, octopods particularly, 

 came to the conclusion that albumin is completely catabol- 

 ized in the intestine and resorbed in the form of aminoacids. 

 These may thereafter according to requirements undergo 

 either combustion or synthesis in the tissues. 



Synthesis of the Products of Digestion. Assuming 

 then, as we seem fully justified in doing, that the dietary 

 protein undergoes an advanced grade of cleavage in the 



32 O. Folin, W. Denis and H. Lymann (Harvard Med. School), Journ. of 

 Biol. Chem., 12, 141, 253, 259, 1912. 



33 H. Pringle and W. Cramer, Journ. of Physiol., 37, 158, 1908. 



34 G. Embden and H. Reese, Hofmeister's Beitr., 7, 411, 1905; A. Bingel, 

 Zeitschr. f. physiol. Chem., 57, 382, 1908. 



33 C. Neuberg and Richter, Deutsche med. Wochenschr., 1904, 499. 



34 0. Cohnheim, Nagel's Handb. d. Physiol., 2, 629, 1907. 



