mar. 1899] PROTOPLASMIC CURRENTS 6- VITAL IORCE 233 



The action of these causes may be tested by both the natural and 

 the synthetic protoplasm. 



A. The use of gummy water is indispensable if one wishes to 

 observe the circulation of protoplasm in the elements of trees, and the 

 movements are generally dependent on the conditions of diffusion 

 (cf. Butschli's foams). 1 The currents of the artificial product vary in 

 accordance with the diffusive power of the substances, the quantity of 

 liquid, and the presence of some large granulations. 



B. The rapidity of diffusion increases, within certain limits, with 

 an elevation of temperature (Graham). The movements of the proto- 

 plasm increase in rapidity between 10 and 22 degrees, becoming 

 slower beyond those limits, and stopping between 45 and 48 degrees. 



I have seen that at a suitably high temperature these currents 

 present themselves even in very viscous liquids. It is evident that 

 oxygen as well as the liberation of heat attendant on respiration are 

 equally necessary to every being. 



C. The paralysis of artificial currents ceases completely with an 

 addition of peptone or a new quantity of salts. 



D. This is an evident principle. It is enough to remember the 

 facts concerning the circulation of sap and blood. The paralysis of 

 internal currents stops life everywhere, decomposition coinciding with 

 an absolute diminution of movement. 



The rapidity of the course of blood through the capillaries is 

 identical with that of the currents of protoplasm, and varies likewise 

 according to conditions, its result being the same — nutrition and life. 



A motionless peripheral layer of serum is observed similar to 

 that apparent in the currents of pseudopodia. 



The difference between latent and oscillating life lies, in short, in 

 the almost absolute or simply partial inhibition of the internal currents. 

 Water, heat, and oxygen are required as in a physico-chemical 

 phenomenon, and I have often suspended the currents in my proto- 

 plasm by means of desiccation or refrigeration for months together. 

 There is then another argument against my theory which regarded 

 movements as a result of the discharges of carbon dioxide — a theory 

 which has certainly been for me a source of fertile suggestion, though 

 I have now given it up. 



The importance of a large quantity of water in internal currents 

 is perfectly demonstrated. I have shown that dilution has a great 

 influence on the rapidity of the granulations in my artificial protoplasm. 



Now, the gray substance contains more water than the substance 

 in the cerebellum, and this has more than the white substance of the 

 brain and medulla (li. Dubois). The neuroplasm has doubtless its 

 currents, and the variations exhibited in their rapidity, as well as the 

 shocks of their molecules and the waves produced, perchance, by the 

 passage of the current from a conductor with a big calibre to a thinner 

 1 See Milne-Edwards, " Anatomie et physiologie coniparee," tome v. p. 105. 



