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



a thread placed in the field of a microscope. At 

 the moment of mixing^ very considerable disturb- 

 ance took place^ accompanied with a whirling 

 motion. This method not offering results which 

 could be easily registered, it occurred to me to 

 cause one solution to flow into the other through 

 a capillary tube or syphon. The apparatus used 

 was of the simplest possible description, consisting 

 of a pair of cylinders connected by a capillary 

 syphon, the effluent end of which was bent 

 upwards. One cylinder was raised slightly above 

 the other to ensure a flow. I have a photograph 

 of the general arrangement adopted. 



No. 2. Solutions of lead acetate and potassium dichromate 

 were allowed to mix in this manner. The latter 

 salt was passed into the former. The capillary 

 syphon was charged with water, and after this had 

 passed through the heavier fluid a series of vortex 

 rings began to be formed at the point of the tube. 

 Later one attached itself to the tube, and others to 

 this, until a tube was built up through which the 

 potassium ' dichromate was passed, without any 

 chemical action taking place, to the top of the lead 

 acetate. This action continued until the system 

 reached an equilibrium. Fearing that I could not 

 show the experiments before the Society, I photo- 

 graphed some of them, and they show exceedingly 

 well the curious growths of lead chromate which 

 were thus produced. With these two substances 

 -to obtain a single tube was most diflflcult, and only 

 a series could be obtained with anything like cer- 

 tainty. 



An experiment was made reversing the fluids. 



