INTRA-ATOMIC ENERGY. 288 



According- to M. Armand Gautier, two drops of tetanic toxine, con- 

 taining 99 per cent of water and onl}^ 1 per cent of the active body, is 

 sufficient to kill a horse. "A gram of this body," he says "would 

 kill 75,000 men." 



Metals in a colloidal state are exactly like toxines or organized fer- 

 ments. Colloidal platinum decomposes oxygenated water, as do cer- 

 tain ferments from the blood; by oxidation it transforms alcohol into 

 acetic acid, as does the Mycoderma aceti. Colloidal iridium decomposes 

 the formate of lime into carbonate of lime, carbonic acid, and hydrogen, 

 as is done by certain bacteria. A still more curious thing is that 

 bodies like prussic acid, iodine, etc., that poison organic fennents" 

 also paralyze or destro}' the action of colloidal metals. It is necessary 

 to invoke all the weight of our classical ideas concerning the invari- 

 ability of chemical species in order not to see, in a body whose prop- 

 erties are so profoundly different from those from which it is derived, 

 a totally new substance. 



It is evident, however, that the opinion of chemists as to the invari- 

 ability of atoms appear^s to rest upon a very solid basis, since, after all 

 the transformations a body may undergo, we may always regenerate 

 the body. Sulphate of copper bears no resemblance to metallic copper, 

 but copper can be formed from it without difficulty. This argument 

 will retain its value so long as we do not succeed in dissociating suffi- 

 cient quantities of matter, or at least as long as we do not possess the 

 physical means for revealing the transformations, often very slight, 

 that occur in a bod}'^ in which a small amount of dissociation has taken 

 place. When a metal is modified by a partial dissociation it is 

 changed too little for us to be able to prove it by the ordinar\' chemi- 

 cal reactions. 



Only physical reactions can give evidence of such modifications. 

 Radium and phosphorescent bodies furnish an excellent proof of this. 

 As concerns radium, for example, we know that in its chemical reac- 

 tions it is entirely identical with barium. It differs from it enor- 

 mously, however, by its radio-active properties — that is to sa}^, b}^ the 

 permanent dissociation of its atoms, which physical means alone can 

 reveal. 



As to the marvellous phenomenon of phosphorescence, it likewise 

 affords an example of substances chemically identical which yet pre- 

 sent an entirely novel physical property under the influence of traces 

 of foreign substances that probably act by producing a connnencement 

 of dissociation. The sulphides of calcium or of l)ariuni are never 



« The action of the poison varies with different toxines. They resist some ener- 

 getic reagents and are influeni-ed by traces of reagents that would seem to possess 

 but little activity. ]\I. Ariiiaiid Gautier has sliown that bodies as violent as prussic 

 acid, corrosive sublimate, and nitrate of silver are without effect upon cobra venom, 

 while mere traces of alkaline matter prevent its action. 



