M. De la Itive on Chemico- capillary Actions. 445 



to suppose that the effect observed is only the result of the che- 

 mical action, more or less modified by the fact that the space is 

 capillary — and in particular that the action can only take place 

 on a small number of molecules at a time and successively, in- 

 stead of acting on the whole of the two solutions at the same time. 

 This is evidently an important point to investigate. It is very 

 probable that the chemical action is modified by the so-called 

 molecular attraction to which capillarity is attributed. It is also 

 possible that this so-called molecular attraction is only one form 

 of affinity — or rather that the two forces are only one, so that in 

 the capillary spaces the liquid is not in the same conditions, 

 physical or chemical, which it presents when it is in mass; thus 

 the action of another liquid on the capillary layer would be quite 

 different from that which it exerts in its ordinary state. It would 

 be an action of the same kind as those of contact, the so-called 

 capillary ones. 



The greater the advance in the study of chemistry the more 

 insufficient do we find the explanations of chemical phenomena 

 that are merely based on the exercise of the force called affinity 

 as hitherto understood. As I have already said, a host of cir- 

 cumstances demonstrate this inadequacy. One of the most re- 

 markable of the phenomena is the modification which the pre- 

 sence in a liquid or a gas of an apparently inert solid brings 

 about in the chemical relations of this gas with others. And, 

 in fact, the limiting surface of a liquid or a gas should have dif- 

 ferent properties from the rest of the layer. Now the charac- 

 teristic of liquids placed in capillary spaces is that of being 

 exclusively formed of limiting surfaces; and therefore it is not 

 very surprising to find that in these conditions their proper- 

 ties become quite different from what they are in their natural 

 state. Considering Clausius's theoretical ideas on the constitu- 

 tion of liquids and gases, those of Deville on dissociation, of 

 Graham on dialysis, and those of Bunsen on the combination of 

 certain gases, without taking into account the older ones of JBer- 

 zelius on catalysis, of Dutrochet and so many more on endosmose 

 and exosmose, we come to the conclusion that we have an entirely 

 new force of chemistry to deal with. It seems therfore premature 

 to endeavour to give a rational explanation of the phenomena re- 

 cently discovered by M. Becquerel by ascribing them to an elec- 

 tro-capillary effect. They are probably only one of the numerous 

 forms of chemico-molecular actions in which the physical con- 

 stitution of the body plays as important a part as its chemical 

 constitution. And even if we rejected all M. BecquerePs theore- 

 tical ideas on this subject, this illustrious physicist would none 

 the less have rendered a great service to science by directing the 

 attention of men of science to these phenomena. 



