THE LYMPH-GLANDS. 405 



atrophy, large quantities of paralactic acid have been found, in 

 addition to a notable amount of leucin and tyrosin. In amyloid 

 degeneration of the organ chondroitin-sulphuric acid has been 

 observed. Biliary pigments are normally not encountered in the 

 liver-cells, but quite commonly they stain these an intense yellow in 

 cases of obstructive jaundice. These various constituents have been 

 studied in the foregoing chapters, and need not be reconsidered at 

 this place. 



THE DIGESTIVE GLANDS. 



The chemical composition of the digestive glands, viz., the salivary 

 glands, the pancreas, and the glands of the stomach and the intes- 

 tinal canal, is essentially expressed in the composition of their specific 

 secretions, bearing in mind, however, that the various ferments exist 

 in the cells as pro-enzymes. The mucin which is furnished by the 

 sublinguaj_and submaxillary glandsandthe small mucous glands of 

 the stomju?lijind^ijLintes^ is similarly present asajnucin- 



ogen. Of common components, we ffncTa certain a moUnToT mineral 

 salts, traces of the common albumins, nucleo-albumins, and nucleinic 

 bases, and in the pancreas, in addition, free fatty acids, small amounts 

 of leucin, tyrosin, inosit, and paralactic acid. In the pancreas a 

 highly complex nucleo-glucoproteid is also found, which yields a 

 somewhat less complex substance of the same character, together 

 with a ooagulable albumin, when the fresh gland is boiled with 

 water. The proteid is held in solution owing to its combination 

 with an alkali, but is precipitated as such on treating with a dilute 

 acid. Its elementary analysis has given the following results : 

 carbon, 43 per cent.; hydrogen, 5; nitrogen, 0.7; and phosphorus, 

 4.5. In addition, the substance contains a considerable amount 

 of iron. On digestion with gastric juice a nuclein remains behind, 

 which is very rich in phosphorus. Among the decomposition- 

 products which result on hydrolysis with boiling hydrochloric acid 

 we find a pentose and a large amount of nucleinic bases, among 

 which guanin is especially abundant. According to Bang, a nucleinic 

 acid can be isolated from the proteid, as also from the pancreas di- 

 rectly, which he terms guanylie acid, as guanin is the only nuclei nic 

 base, that can be obtained on decomposition. Its composition is : 

 carbon, 34.18 per cent. ; hydrogen, 4.43 ; nitrogen and phosphorus, 

 7.64, which would correspond to the formula C 22 H 34 N 10 P 2 O 17 . On 

 decomposition the substance yielded at least 35 per cent, of guanin, 

 about 30 per cent, of a pentose (calculated as glucose), and as a third 

 product, ammonia. 



THE LYMPH-GLANDS. 



The lymph-glands comprise the lymph-glands proper, the thymus 

 gland, and the spleen. Their fibrous framework, as I have pointed 

 out (page 383), consists essentially of reticulin, but also contains 

 fibres of collagen and elastin. The composition of the cellular ele- 



