190 Report 8. A. A. Advancement op Science. 



organisms. Firot of all the protoplasm. The absence of an internal 

 elasticity, the diop form of fractions of protoplasma, indiciite its liquid 

 state. It is a very complicated system of colloids in company with 

 enzymes and crystalloids, characterised by a perpetual variability, so that 

 it is physically and chemicall}' dijfferent in ever^^ moment. In no case 

 are the correlations between physical and chemical processes so numer- 

 ous and the energies so concentrated as in a cell. Numerous chemical 

 compositions and decompositions of different kinds take place in very 

 small space. This is only possible b}'^ the colloid nature of the protoplasma 

 and the presence of intra-cellular enzymes. Substances which enter as 

 crystalloids through the. external colloidal protoplasma layer are con- 

 densed into high molecular colloidal forms, and they have to remain in 

 the interior, for they do not diffuse. For instance, sugar enters crystal- 

 loid into the liver cells ; it is polymerised there to the colloidal glycogen, 

 and it only leaves after having been transforined into a crystalloidal 

 state again. Or, adversely, substances — albuminoids, for instance — 

 are decomposed by enzymes to chemical bodies with a low molecular 

 weight and osmotically active. As soon as the osmotical partial pres- 

 sure for these substances is lower outside they diffuse through the 

 protoplasma and membrane into the interstitial liquid. 



The enz3'mes are fixed in the interior by means of their impotence 

 of diffusion as a consequence of their colloidal nature. 



There is even a possibility of localisation of the enzymes and 

 chemical I'eactions within the cell by the foamy structure of the proto- 

 plasm (Biitschly). The walls of this foam would act as semi-permeable 

 membranes, and they would be permeable for certain ions, and not for 

 others; not at all oi' but little permeable for colloids, especially fur the 

 enzymes. 



That is the general principle of the common metabolism as it 

 happens in every living cell. A number of experiments were carried 

 out especially to study cell-functions from a physical-chemical stand- 

 point. The influence of the ions is prominent in physiological and 

 pathological instances. I recall only the artificial fertilisation of eggs 

 simply b}' ions in a certain concentration (Loeb, Delage), the activating 

 or procrastinating influence of electrolytes on phagocytosis (Hamburger 

 and Hekma), and muscular twitchings (Loeb), the permeability (Ham- 

 burger, etc.), and the conditions of permeabilisation of the erythrocyte 

 membrane (Frei). 



(/■) The AlE>jnuANES. 



I have already stated that colloid particles condense in the surface 

 and decrease the su)'face tension. The superficial condensation can go 

 so far as to foi-m a film, which has the physical character of a solid — 

 elasticity, for instance. Such membranes are especially formed by 

 albuminoid solutions, the surface of which is the limit towards a 

 medium with a surface tension, different from its own (air or any 

 liquid) (Ramsden, Devaux, IVIetkalf). 



Attention has receJitly been flrawn to these facts, to the conditions 



