92 THE CHEMISTRY OF THE TISSUES AND ORGANS. 



methods and results. He finds that absolute alcohol, which Frunkel 

 used for extracting the active substance from the gland, only dissolves 

 it in traces ; and that the prolonged action of alcohol, especially 

 if heat is employed, renders the material physiologically inactive, 

 though it still continues to give the colour reactions enumerated 

 above. He is inclined to consider the substance to be a derivative 

 of piperidine, not of pyrocatechin, as Frankel supposes. Piperidine 

 certainly produces a marked rise of blood pressure, like suprarenal 

 extract. 1 



Pancreas. This organ is alkaline during life, and rapidly becomes 

 acid after death. The solids are like those usually obtained from cellular 

 organs, namely, proteids (for the phospho-gluco-proteid separated from 

 the gland by Hammarsten, see p. 64) ; extractives (guanine, 2 xanthine, 

 hypoxanthine, leucine, 3 tyrosine, uric acid, lactic acid, inosite), and a 

 small proportion of inorganic salts. 



Salivary glands. The subinaxillary gland yields proteids, of which 

 the most abundant is a nucleo-proteid ; 4 the cells also contain mucinogen, 

 which passes as mucin into the saliva. The parotid cells contain no 

 mucin. A small amount of mucin is, with gelatin, obtainable from the 

 investing connective tissue. 



The kidneys. During life the reaction of renal tissue is alkaline ; 

 after death it rapidly becomes acid, especially the medulla. 5 



Gottwalt 6 gives the following table relating to the percentage 

 composition of kidney tissue freed from blood : 



Proteids 1M85 to 12*217 per cent. 



Gelatin 0-996 1'849 



Mucin ...... Traces. 



The following extractives have been obtained by various observers : 

 xanthine, hypoxanthine, creatine, taurine, leucine, cystin, urea, uric acid, 

 glycogen, and inosite. 



The kidney also contains a small proportion of inorganic salts (01 

 to 07, Oidtmann). 



The proteids of kidney tissue. 1 These are very like the proteids of 

 other glands, and consist of cell globulin, coagulable by heat at 52 C., 

 and a nucleo-proteid. This is far the more abundant ; it coagulates at 

 63 C. ; it may be prepared by either the acetic acid or sodium chloride 

 method. It contains 0*37 per cent, of phosphorus, and produces, like 

 other nucleo-proteids, intravascular coagulation. 



The lungs. The chemical constituents of these organs call for no 

 special notice. 8 



The testis. Chemically, the testis is mainly composed of proteids, 



1 This was shown independently by Tunnicliffe, Cenlralbl. f. PhysioL, Leipzig, 1897, 

 Bd. x. S. 777. 



2 Scherer, Ann. d. Chem., Leipzig, Bd. cxii. S. 276. 



3 Virchow, Frerichs, and Stadeler, see Hoppe-Seyler, "PhysioL Chem.," S. 260. These 

 substances are present in the fresh organ, and are not, as in -the spleen, the result of putre- 

 faction. 



4 Hammarsten, Ztschr. f. pliysiol. Chem., Strassburg. Bd. xii. S. 163. 



5 Halliburton, Journ. PhysioL, Cambridge and London, 1892, vol. xiii. p. 806. 

 Liebermann states that the normal reaction of kidney tissue is acid, Arch. f. d. ges. PhysioL, 

 Bonn, Bd. 1. S. 55. 



6 Ztschr. f. pliysiol. Chem., Strassburg, Bd. iv. S. 431. 



7 Halliburton, loc. cit. 



8 " On Lecithin in Lungs and Sputum," see Zoja, Gazz. med. di Torino, 1894, 

 vol. xlv. 



