264 PKOOEBDINGS OF THE 



the steel mirror was found to lose a little light. He could 

 not say anything about the keeping qualities of the mirrors, 

 but he had two small ordinary steel mirrors about eighty years 

 old which were still in good condition. Mr. Nelson then explained 

 the double reflection which is obtained with an ordinary mirror. 

 If the light is reflected at the polarising angle, the reflection from 

 the glass surface is polarised, and can be extinguished with a 

 nicol, while the image from the silver surface remains unafiected 

 in either case. The thanks of the Club were accorded to Mr. 

 Nelson for his note. 



The President then called on Mr. S. C. Akehurst to read his 

 paper on " The Larva of Chaohorus crystalUnus (de Geer) [Corethra 

 plumicornis F.]." 



A hearty vote of thanks was accorded to Mr. Akehurst for 

 his paper. 



At the 560th Ordinary Meeting of the Club, held on April 12th, 

 the President, Dr. A. B. Rendle, M.A., F.K.S., in the chair, the 

 minutes of the meeting held on March 8th were read and con- 

 firmed. 



Messrs. Thomas Henry Howells, Henry F. Sprinyer, Arthur 

 George Morey Weale, Frederick Nathaniel Davidson, Albert 

 Nelson Williamson and George Bagster were balloted for and duly 

 elected members of the Club. Six nominations were read for the 

 first time. 



The Hon. Secretary read a list of the recent additions to the 

 Library. The members expressed their appreciation of Messrs, 

 Watson's exhibition and demonstration at the last Gossip Meeting, 

 and the Secretary announced that Messrs. Baker would give an 

 exhibition at the next Gossip Meeting on April 26th. 



The President read an obituary notice by Mr. E. M. Nelson of 

 Mr. G. E. Mainland, who died on December 22nd, 1920, at the age 

 of eighty. He left London nineteen years ago, and so was not 

 likely to be known to any but the older members of the Club, of 

 which he was a member for many years. He was a keen micro- 

 scopist and an excellent exhibitor. He discovered the diatoms of 

 which Sozodont tooth powder is composed. The Secretary was 

 directed to send a letter of condolence to Miss Mainland. Mr. 

 Hilton said that he knew Mr. Mainland well. Owing to a nervous 

 breakdown he went to the seaside, and his doctor suggested his 



