EXPERIMENTS WITH RADIUM 91 



densation or formation of a complex aggregate 

 round a nucleus, itself the seat of an electro- 

 magnetic disturbance, as in radio-active particles 

 that might set up an aggregation of molecules, 

 probably of an unstable kind, in its vicinity. 



The most promising step to take appeared to 

 be to introduce some radium salt into a tube 

 containing glycerine, and then suddenly to cool the 

 liquid, which would thus have every opportunity 

 of condensing round the ions from the radium 

 embedded in the glycerine ; and perhaps also the 

 aggregates contemplated would have a similar 

 opportunity of being formed by the intense 

 electromagnetic pulses set up, or possibly by some 

 catalytic actions. Crystals 0/ glycerine were thus 

 produced, but it was found that the radium was 

 not necessary, the low temperature being sufficient 

 to enable them to form. On being removed from 

 the cooling chamber and allowed to stand at the 

 ordinary temperature of the room, they rapidly 

 disappeared in about five minutes or so. Dr. 

 J. H. Gladstone exhibited to the Chemical Society, 

 1866, some crystals of glycerine which were found 

 in a tun from Vienna. Several generations of 

 these have been obtained and preserved in various 

 laboratories. The manner in which they first 

 appeared is not known. They were quite difi"er- 

 ent from those obtained by liquid air, and this 

 experiment was also made with gelatin. Micro- 

 scopic crystals were thus easily produced by 

 immersion in liquid air, and the outward appear- 



