On Immunity viitli Special Reference to Cell Life. 



433 



actual chemical cleavage. The gliicoside itself yields no trace of 

 sugar when extracted in indifferent solvents. In a quite analogous 

 manner the sugar entering into the constitution of albuminous 

 bodies (glycoproteids) cannot be obtained by any method of ex- 

 traction; at least, not until chemical decomposition has previously 

 taken place. It is therefore generally easy, by means of extraction 

 experiments, to decide whether any given combination in which cells 

 take part is or is not a synthetic one. If alkaloids, aromatic amines, 

 antipyretics, or aniline dyes be introduced into the animal body it is 

 a very easy matter, by means of water, alcohol, or acetone, according 

 to the nature of the body, to remove all these substances quickly and 

 easily from the tissues. This is most simply and convincingly demon- 

 strated in the case of the aniline dyes. The nervous system stained 

 with methylene blue, or the granules of cells stained with neutral red, 

 at once yield up the dye in the presence of alcohol. We are therefore 

 obliged to conclude that none of the foreign bodies just mentioned 

 enter synthetically into the cell complex ; but are merely contained in 

 the cells in their free state. The combinations into which they enter 

 with the cells, and notably with the not really living parts of them 

 (Kupffer's paraplastic portions), are very unstable, and correspond 

 usually only to the conditions obtaining in solid solutions, while 

 in other cases only a feeble salt-like formation takes place. I myself 

 in 1887 placed on a siue footing the fact that the nervous system and 

 the fatty tissues allow of alkaloids and aniline dyes being mechani- 

 cally shaken out of them, as in the poison-detection process of Stas 

 and Otto. 



Hence ^^^th regi.rd to the jjharmacologically active bodies in general, 

 it was not allowable to assume that they possessed definite atom 

 groups, which entered into combination with corresponding groups 

 of the protoplasm. This corresponds, as I may remark beforehand, 

 with the incapacity of all these substances to produce antitoxines in 

 the animal body. We must therefore conclude, that only certain 

 substances, food-stuffs po/r excellence, are endowed with properties 

 admitting of their being, in the previously defined sense, chemi- 

 cally bound by the cells of the organism. We may regard the cell 

 quite apart from its familiar morphological aspects, and contemplate 

 its constitution from the purely chemical standpoint. We are obliged 

 to adopt the view, that the protoplasm is equipped with certain atomic 

 groups, whose function especially consists in fixing to themselves certain 

 food-stuffs, of importance to the cell-life. Adopting the nomenclatiue 

 of organic chemistry, these groups may be designated side-chains. 

 AVe may assume that the protoplasm consists of a special executive 

 centre (Leistungs-centrum) in connection Avith which are nutritive 

 side-chains, which possess a certain degree of independence, and which 

 may differ from one another according to the requirements of the 



