28 



containing cylinder. This tube was composed of minute 

 but well defined crystals. I found it impossible to retain 

 it in its perfect shape for inspection here. 



9. Sodium Carbonate on Barium Chloride. A very 

 similar action to that mentioned in experiment 7, but at no 

 time was a transparent substance noted, the growth being 

 quite opaque and not palpably crystalline. 



10. Hydrochloric Acid on Sodium Silicate. Here a well 

 marked action took place, and a tube of silica was produced, 

 a portion of which I am able to show. 



11. Knowing the Silica produced by the action of Ammo- 

 nium Chloride on Sodium Silicate was much denser than 

 that obtained in the previous experiment, I caused these 

 substances to act on each other, and succeeded in obtaining 

 a very long tube of Silica of considerable thickness. I am 

 able to show this also. 



12. Ferricyanide of Potassium on Ferrous Sulphate. 

 Notwithstanding the extreme lightness of the blue precipate 

 produced by these solutions a perfect tube was obtained, 

 which reached the surface of the Ferrous Sulphate. 



Many experiments on the above lines will readily suggest 

 themselves, but I think I have described sufficient to call 

 attention to this, to me, novel method of experiment, and I 

 must leave it to some future occasion to describe such others 

 as may show any peculiarities worth noting. I purposely 

 refrain from making any theoretical deductions, with the 

 one exception, that it is pretty certain that these phenomena 

 are inseperably connected with vortex action, the tubes 

 being undoubtedly built up of a series of vortex rings. 



