44 



friend, and he knew that the Chib had lost a member whose 

 interest in its welfare was of the most sincere and practical 

 character. 



The President said that the testimony borne by two Secretaries 

 of the Club was very pleasing to hear, and it would no doubt 

 find an echo in the minds of many of the older members of the 

 Club. For himself he could not say that he possessed so much 

 knowledge of their late friend, but he should always remember 

 the kind courtesy and attention he had always received from 

 him. 



Mr. J. E. Barnard gave an interesting account of improvements 

 in the Electric Arc Lamp which had been carried out by himself 

 and Mr. T. A. B. Carver, in order to render it serviceable for 

 Photomicrography Hitherto there had been very great difficulty 

 in using this light for the purpose, because of the difficulty of 

 keeping the position of the arc constant, and of securing a 

 sufficiently small and uniform source of light. After many 

 experiments they had devised a form of lamp which appeared 

 to answer the purpose admirably. In this the distance apart of 

 the carbon points was regulated by hand, and their position 

 could by the same means be easily controlled, so that by reference 

 to cross-wires on a glass screen the source of light could be 

 always kept in the same place, whilst the oblique position in 

 which the carbons were set enabled the small point of intense 

 light from the incandescent crater of the positive carbon to be 

 used as a source of unvarjdng and steady illumination of small 

 area, but very great intensity. Photographs of the form of lamp 

 employed were shown upon the screen, and the magnified images 

 of the carbon points were projected upon another screen to show 

 the varying effects produced by alterations in the distances and 

 positions of the points. A number of excellent lantern slides 

 of high-power objects, bacilli, etc., taken by the means described, 

 were also exhibited on the screen. 



Mr. E. M. Nelson said he could entirely endorse what Mr. 

 Barnard had said with regard to the necessity in Photomicro- 

 graphy of having a steady source of light. He had not used the 

 Arc Lamp himself owing to its unsteadiness. He had experienced 

 the same difficulty with the lime light; but by reducing the 

 pressure of the gas to about 1 inch, and using a very hard lime 

 and a jet with a medium-sized bore, he got a fairly steady light. 



