PROCEEDINGS OF THE SOCIETY. 1121 



■ Mr. Crisp reminded the meeting that it was arranged some time 

 ago that they should give, in the Journal, photographic portraits 

 of all the Presidents of the Society ; a full-page plate of Sir R. 

 Owen, as tlie first President of the Microscopical Society, and another 

 of Mr. Glaisher, as the first President of the Royal Microscopical 

 Society after its charter had been granted, the other Presidents being 

 given in two groups of eight. Proofs of the portraits were upon the 

 table for the inspection of the Fellows. In view of criticism as to 

 the general eflect of the groups, he might mention that the trouble 

 which had been required to get them into order was beyond anything 

 that could have been supposed, arising from the very various charac- 

 ter of the originals and otherwise, and their thanks were largely due 

 to Mr. J. Mayall, jun., for the pains he had taken in the matter. As 

 to the style of the particular portraits, he might say that nearly all 

 the photographs had been selected either by the persons themselves 

 or by their families, as being those which they considered the best. 



The President said that the death of Prof. Robin, announced at 

 the previous meeting, created a vacancy in their list of Honorary 

 Fellows which it was proj)osed to fill up by the election of Prof. H. 

 de Lacaze-Duthiers, whose nomination would be suspended in the 

 usual way, and brought forward for ballot at their next meeting. 



Mr. C. Beck exhibited a modification of the " Star " Microscope, 

 which could be folded up into a small compass as a portable Micro- 

 scope. 



Mr. Crisp exhibited a Microscope in which the adjustment was 

 made by winding a piece of catgut on an axle. 



Mr. John Mayall, jun., exhibited and described the Trouve- 

 Helot electric lamp for microscopic use, worked by a portable battery 

 of six cells, each containing two zincs and three carbons. When 

 not in use the elements were lifted out of the bichromate solution 

 and retained in position at the top of the vulcanite case, whilst by a 

 simple arrangement they could be lowered into the exciting liquid 

 when needed, and any number of the cells could be connected up as 

 required. The photophore consisted of a small incandescence lamp, 

 fitted in a cylinder, with a condcnsing-lens in front. The best way 

 to use it was to commence with three cells, and then, as the light 

 got weak (which would occur in about an hour), to increase the num- 

 ber in circuit until the wliole six were in use, each additional cell 

 enaljling the light to be kept up for about twenty minutes, or about 

 two hours in all, with fairly continuous amount of light. He tliour^ht 

 that M. Trouve had, to some extent, sacrificed cfTicioncy to portability. 

 The cl;<jnitc case for tlie colls appeared far too sliglit for the pui'posc, 

 wjnsidering that it contained sulphuric acid. He liad the promise of 

 one of the Jablochkoff dry batteries for exhibition at the Soir<5o, 



