9G ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



ally by the forces at the free surface will form rings, but 

 also that a vortex movement can arise in the process of dif- 

 fusion by a variation in density and pressure without the 

 aid of initial angular velocities. The apparatus employed 

 to produce the rings consists merely of a small glass tube, 

 slightly smaller at one end, having a bit of cotton wedged 

 in nearer the larger end, over which a piece of rubber tube 

 is slipped. The apparatus being filled by means of the 

 mouth with liquid, it can be ejected in such a way as to 

 form the rings either at or beneath the surface of the liquid. 



De Komilly has made some curious experiments on capil- 

 lary action. He finds that if a bell-jar be covered at bot- 

 tom with a cotton netting whose meshes are from one-eighth 

 to one-twelfth inch in diameter, water drawn up into it will 

 remain suspended, a well -pronounced meniscus being ob- 

 servable at each mesh. Moreover, although the strength 

 of capillary attraction diminishes with the temperature, the 

 water in the jar may be boiled by placing a Bunsen burner 

 beneath the netting without falling through it. Special ap- 

 paratus is needed to maintain the level, which the author 

 figures and describes in his original paper. 



De la Grye has studied the changes of form which are 

 produced when two liquids of different densities are super- 

 posed and rotated with different velocities. If the more 

 viscous of the two be uppermost, as in the case of oil and 

 water, the oil becomes thinner in the centre, and if a more 

 viscous liquid still, as a solution of gutta-percha in benzene, 

 be used in place of oil, the appearances presented recall re- 

 markably those of sun spots. If, however, the more viscous 

 liquid be below, as, for example, oil and alcohol, the upper 

 layer becomes thicker in the middle. It would hence ap- 

 pear that if the solar spots are formed by centrifugal force, 

 the photospheric layer must have more cohesion than the 

 gaseous substratum beneath it, and than the overlying chro- 

 mosphere. 



3. Of Gases. 



Mendelejeff has made an extended investigation into the 

 accuracy of Boyle's law of gaseous compression, special ap- 

 paratus being used for the purpose, in which all possible 

 causes of error were eliminated, and which allowed the most 

 perfect accuracy of measurement. The experiments were 



