4 MR. R. S. DALE ON SOME NOVEL PHENOMENA OF 



thick tube of ferrous hydrate was formed, which I 

 am able to show you, as it is by no means fragile. 

 It has, of course, been, since out of the fluid, par- 

 tially converted into ferric oxide. 



No. 6. Sodium carbonate on copper sulphate. In this 

 case a crystalline copper carbonate was obtained of 

 two shades, one a bright blue resembling azurite 

 (if it be not actually that substance), and another 

 a bright green resembling malachite. I am able 

 to show this tube. 



No. 7. Ammonium sulphide on copper sulphate. An 

 action closely resembling, in many particulars, the 

 action of ammonia on ferrous sulphate. 



No. 8. Sodium carbonate on calcium chloride. The com- 

 mencement of the action was marked by the for- 

 mation of a perfectly transparent and highly 

 refractive sheath of calcium carbonate, which did 

 not show any signs of crystallization until about 

 half an inch in length. On examination, after the 

 lapse of about twelve hours, a crystalline tube of 

 calcium carbonate had made its way to the top of 

 the 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. 



No. 9. Sodium carbonate on barium chloride. A very 

 similar action to that mentioned in experiment 

 No. 7, but at no time Avas a transparent substance 

 noted, the growth being quite opaque and not 

 palpably crystalline. 



No. 10. Hydrochloric acid on sodium silicate. Here a 

 well-marked action took place, and a tube of silica 



