282 INTRA-ATOMIC ENERGY. 



very active in a dose of a three hundredth of a niillij^rani of the 

 metal to a liter of water — they take on properties so intense and pecul- 

 iar, so difi'erent from those which they possess in an ordinary state, 

 that we can only compare them to certain org-anic compounds called 

 diastases. It is found also that they act by their presence alone — that 

 is to say, Avithout appearing in the final product of the reactions. 

 Chemists use the term 'catalytic action'' to explain analogous facts. 

 The body supposed to act only by its presence is perhaps the seat of 

 special atomic disaggregations which are not shown by reagents. We 

 will indicate further on experiments on phosphorescence that support 

 this consideration. 



These metals in a colloidal state are obtained by various processes, 

 the severest of which is the passing through distilled water of an electric 

 arc between two poles made of the metal to be transformed, platinum 

 or gold, for example." After a certain time the water contains, in a 

 form totally unknown, something derived from the particles of the 

 metal, and that in the infinitesimal dose I have mentioned above. The 

 liquid is colored, but it is impossible to separate anj^thing from it by 

 filtration or to perceive by the microscope any particles in suspension, 

 which loads us to suppose that these particles, if they exist, are less 

 than a wave length of light — that is to say, the thousandth of a milli- 

 meter. It does not seem possible to admit that the metal thus trans- 

 formed is in a state of solution, ^ for the water that contains it presents 

 none of the characters of a solution, such as a changing of its freezing 

 or boiling points, the tension of its vapor, etc. In my opinion, the 

 metal is found in the state of matter that has suffered a commence- 

 ment of dissociation, and it is exactly for that reason that the colloidal 

 metal prepared by the electric arc possesses none of the qualities of 

 the body from which it was derived. Colloidal platinum or gold are 

 certainly not ordinary gold or platinum, tliough they are made from 

 those metals. 



The properties of these colloidal metals are, indeed, without any 

 analogy with those of a salt or even of a metal in solution. B}^ certain 

 of their reactions they resemble organic compounds rather than brute 

 matter. That is the reason why they have been compared to the 

 toxines, a kind of diastases of unknown chemical composition gener- 

 all}^ formed b3' bacteria, from which they can be separated by filtration, 

 and which in imponderable doses produce tremendously active efi'ects. 



« The metals called "colloidal," like silver, for example, that are now found in 

 commerce, are really simple chemical combinations and have very different 

 properties. 



''This would not be theoretically impossible, notwithstanding the supposed insol- 

 ubility of metals, since a 20-franc piece placed in distilled water for a short time 

 leaves in the latter traces of the copper which it contains as alloy in a quantity 

 that can not be shown by reagents, but which is still sufficient to poison certain aigee. 



