1074 PROCEEDINGS OF THE SOCIETY. 



mechanism of the new Microscope, it would be in the direction of 

 strengthening some of the parts which seemed rather too weak. It was a 

 vital point to have the optic axis exactly at right angles to the stage, but he 

 feared the cross-arm support of the body-tube was very slight, and would 

 be easily bent in the hurry of setting up or packing away. The attachment 

 of the body-tube to the cross-arm seemed to him defective, and reminded 

 him of some of the least successful of previous constructions. The want of 

 a fine-adjustment might be met to a great extent by the application of a 

 smooth -working draw-tube, as in Swift's Miniature Microscope. 



The President said he must express his agreement with Mr. Mayall's 

 suggestions for the improvement of the Microscope. Speaking after much 

 experience in giving class demonstrations with the Microscope, he should 

 consider a paraffin lamp was a dangerous thing to use in a class, in the 

 manner shown, amongst a number of youths, who were not always particu- 

 larly careful. He thought, if used in that way, some less dangerous oil or 

 some other source of artificial light should be provided. 



Mr. Nelson also exhibited and described the new photomicrographic 

 camera, designed by Mr. C. L. Curties and himself. He also exhibited a 

 negative of the proboscis of the blow-fly, which, he thought, would bear the 

 closest examination (supra, p. 1025). 



Prof. Crookshank said that he should like to examine the apparatus a 

 little more closely after the meeting. He felt much obliged to Mr. Nelson 

 for introducing a cheap and efficient method to their notice. He was him- 

 self more and more impressed with the value of photomicrography, and 

 therefore welcomed every additional aid to its extension. So far as he could 

 judge, this apparatus was simple, and enabled the process to be carried on 

 with very little loss of time. This alone would be a great gain to patholo- 

 gists who did not want to perform feats, but to get the greatest accuracy of 

 detail recorded in as little time as possible. He thought that, especially 

 with regard to bacteriology, the results obtained by photography had not 

 been simply to obtain artistic pictures. Koch photographed the flagella of 

 some of these minute organisms, and in this way obtained demonstrations 

 of the existence of the flagella, which had not been believed in by many. 

 He should like to say that at the Conversazione on the 23rd inst., he pro- 

 posed to throw upon the screen a number of photographs of bacteria, to 

 show that the results obtained by photography might be used for the pur- 

 poses of teaching. He did not say that in all cases the results gave pictures 

 as sharp as could be desired, but whilst it had been stated that one reason 

 for disbelieving in the value of such researches was because they showed no 

 morphological differences, he thought he might safely leave those to judge 

 of the matter who would see what he proposed to show them on the 23rd. 



Mr. Nelson further exhibited a new eye-piece which he had devised 

 [supra, p. 928). 



The President said that, as their time was already so far advanced, they 

 must omit some of the minor matters on the programme for the evening, 

 in order that they might hear Mr. Beaumont, who had come up to London 

 to give them an account of his observations on the development of Amoehse. 



Mr. C. E. Beaumont then exhibited and described his new form of slide 

 for observing living organisms, and read a paper in which he claimed to 

 have observed the development of an Amoeba into an Actinojphrys, and then 

 into a Difflugia and an Arcella. 



