208 procekdinos of societies. 



Makchesteu Literary and Philosophical Society. 



microscopical section. 



March nth, 1862. 



E. W. BiKNET, Esq., F.E.S., E.G.S., in the Chair. 



Twelve specimens of soundings were received from Captain 

 George Randall, of the barque " Brazil," taken on the north 

 coast of Brazil ; also five specimens from Captain George Murray, 

 of the ship " Finzel," taken off Eobin Island, Table Bay; coasts 

 of Sumatra, Java, and St. Helena. 



Mr. H. A. Hurst made a donation of eight slides of diatomacese 

 of various kinds ; also specimens of fibre from the Bombax, or 

 East Indian cotton tree, and the fibre of the Asclepias Syriacus, 

 from Bengal. Some conversation arose upon the adaptation of 

 these fibres as substitutes for cotton, but, although fine and silky, 

 there is not sufficient strength in the staple to render them fit for 

 manufacturing purposes. 



Mr. Blandford presented, through Mr. Hurst, a number of 

 specimens of the tongues of mollusca from Burmah, upon Avhidh 

 Dr. Thomas Alcock reported that there were four species, two 

 being fresh-water — Melania variabilis ; a species of Paludomus ; 

 and two land shells, different species of Cyclophorus. 



Cyclophorus belongs to a section of the order Pulmonata, 

 distinguished by having an operculum or door to the mouth of the 

 shell, and by having a type of teeth similar to that of the 

 Pectinibranchiata. Cyclostoma elegans is a British representative 

 of the same group. 



Mr. Cheetham exhibited a prism, which he uses to illuminate 

 objects under the microscope with the variously coloured lights of 

 the spectrum in succession, instead of ordinary light. He finds 

 that details of structure are more distinctly brought out by some 

 of the colours than others ; the blue and green rays are also very 

 pleasant to work with, and easily varied by throwing the required 

 part of the spectrum on the mirror below the stage. 



Mr. Sidebotham brought before the notice of the meeting Mr. 

 Petschler's process for producing vegetable forms with crystals of 

 bichromate of potash in gelatine, which was discovered by him in 

 the preparation of glass plates for photographical purposes, and 

 exhibited at the microscopical soiree given to the British 

 Association at the last meeting. Specimens on large glass plates 

 were handed round, which, when magnified, aptly represent 

 mosses, ferns, and algae, in beautiful ramifications, which vary in 

 many ways, dependent upon the strength of the solution, 

 temperature, state of the atmosphere, and other causes. Mr. 



