8 Proceedings. 



on minute particles of carbon, and, according to a carefully 

 demonstrated theory, becomes divided into countless minute 

 spheres, upon the surface of which is precipitatad a film of 

 tarry matter due to the condensation of some of the hydro- 

 carbon vapour. These spheres are so minute as to be 

 invisible in the most powerful microscope. Professor Aitken 

 filled two vessels, one with London air and one with air 

 filtered through cotton-wool, and into these vessels he passed 

 equal quantities of steam. In the filtered air it was trans- 

 parent ; in the ordinary air it became like a cloud. The 

 condensation from the filtered an- wetted the sides of the 

 vessel ; that of the unfiltered air occui-red upon the minute 

 invisible particles of solid matter suspended in it. The most 

 potent cloud-producer was sulphur ; its fog was so dense that 

 it was impossible to see through a thickness of six or seven 

 yards. 



The vapour thus formed has a greater specific gravity than 

 air, and consequently has a steady downward tendency, and 

 with it brings the carbon, carbonic acid, and sxilphurous acid, 

 which in Loudon are generated in such large quantities. 



Evening Meeting. — Februaey 17th, 1888. 



The company of young people was specially invited. 



Mr. Cyril Frith exhibited a series of lantern-slides illus- 

 trating ' Homes without Hands.' The pictures included the 

 burrows of beasts, nests of birds, nests of insects, cocoons, &c., 

 and descriptions were given by Mr. T. P. Newman and Mr. 

 A. J. Crosfield. 



Mr. Frith also showed some fine photographic slides 

 illustrating Egyptian temples. 



Evening Meeting. — Mabch 16th, 1888. 

 Mr. Linnell gave some particulars of the Club's excursion 

 on August Gth, 1887, to Norbury Park. Amongst the plants 



