266 LECTURE XII. 



fied in calling these processes autolytic. We only know that the organism 

 is capable of mobilizing ferments which take care of foreign material, and 

 by decomposing and reducing the complex molecules, prepare it for assimi- 

 lation. In fact, in pneumonia, during resolution the bronchial tubes seem 

 to possess functions very analogous to those of the intestine. It would 

 be better, for the present, to restrict the term " autolysis " to the ferment 

 action of the cells in the tissues, which follows some time after death. 

 It is like the works of a clock, whose spring has been released and sud- 

 denly runs down. 



Amino acids have recently been found in the urine during various dis- 

 eases. If we summarize these observations, we will obtain the impression 

 that the metabolism has been deranged by lack of oxygen. Thus, tyrosine 

 is found in the urine after prolonged, deep narcosis, during the coma of 

 a diabetic, etc. 1 



While these cases represent merely isolated cases of the appearance of 

 individual amino acids, due to temporary derangements, and which are not 

 at all permanent, we, however, also know of a derangement in metabolism 

 in which a greater or less amount of an amino acid is always present in 

 the urine. This occurs during cystinuria. Cystine 2 is found in the urine 

 during this rather rare disturbance in the decomposition of albumin. 

 Small amounts of this compound seem to be always present in urine. 3 In 

 cystinuria, however, the quantity is very largely increased, and often 

 leads to the formation of calculi. There is not the least doubt but that 

 this cystine originates from albumin. It, like the albuminous cystine, is 

 an a-diamino-/?-dithio'dilactylic acid. Emil Fischer and Umetaro Suzuki 4 

 have recently established the identity of the two substances. 



The significance of cystinuria was long in doubt. The discovery of 

 L. von Udransky and E. Baumann 5 that other di-amines (putrescine and 

 cadaverine) are present in the urine during cystinuria, for a long time led 

 to the assumption that cystinuria is caused by an increased intestinal putre- 

 faction. Cystine, according to this assumption, is split off from albumin 

 in the intestines and absorbed as such. To-day we know that the forma- 

 tion of amino acids is a normal function of the alimentary tract, in no case 

 causing their elimination in the urine. The di-amines mentioned are by 



1 E. Abderhalden: Z. physiol. Chem. 44, 17 and 40 (1905); 45, 468 and 471 (1905). 



2 W. F. Lobisch: Ann. 182, 231 (1876). A. Niemann: Deut. Arch. klin. Med. 18, 

 232 (1876). W. Ebstein: 19, 138 (1877); 30, 594 (1882). B. Hester: Z. physiol. Chem. 

 14, 109 (1890). A. Loewy and C. Neuberg: ibid. 43, 338 (1904). C. Alsberg and O. 

 Folin: Am. J. Physiol. 14, 54 (1905). E. Abderhalden: Z. physiol. Chem. 38, 557 (1903). 

 E. Abderhalden and A. Schittenhelm : ibid. 45, 468 (1905). 



3 Stadthagen: ibid. 9, 29 (1885). E. Goldmann and E. Baumann: ibid. 12, 254 

 (1888). 



4 E. Fischer and U. Suzuki: ibid. 45, 405 (1905). 



6 L. v. Udransky and E. Baumann: Z. physiol. Chem. 13, 562 (1889). 



