92 THE CHEMISTRY OF THE TISSUES AND ORGANS. 
methods and results. He finds that absolute alcohol, which Frankel 
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. 6-4) ; extractives (guanine, 2 xanthine, 
hypoxanthine, leucine, 3 tyrosine, uric acid, lactic acid, inosite), and a 
small proportion of inorganic salts. 
Salivary glands. — The submaxillary 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 ...... 11T85 to 12*21 7 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 (OT 
to - 7, Oidtmann). 
The proteids of hid 'urn tissue? — 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 - 37 per cent, of phosphorus, and produces, like 
other nucleo-proteids, intravascular coagulatii >n. 
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 TunniclitFe, Centrum, f. Physiol., Leipzig, 1S97, 
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. physiol. 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. •">•">. 
6 Ztschr.f. physiol. Chem., Strassburg, Bd. iv. S. 431. 
7 Halliburton, loc. cit. 
8 "On Lecithin in Lungs and Sputum," see Zoja, Gaze. med. di Torino, 1894, 
vol. xlv. 
