PROCEEDINGS OF THE SOCIETY. 185 



Mr. Crisp exhibited Klein's Heating Microscope for observing 

 crystals at bigb temperatures ; Kunckel d'Herculais' compressor, and 

 Verick's apparatus for enabling four photographs to be taken of the 

 same object. 



Mr. J. Mayall, jun., said that the intention of the latter apparatus 

 was to enable four ditferent plates to be used, so as to give a ditierent 

 length of exposure to each, or to photograph different parts of the 

 same object without loss of time. 



Dr. Maddox said that at the request of his friend Dr. Mercer, of 

 Syracuse, he had brought to the meeting for exhibition a series of 

 photographs of inked surfaces covering pencil lines. A note descrip- 

 tive of the photographs was read, and the specimens in illustration 

 handed round for inspection. 



Mr. Crisp said that a somewhat similar case was recorded last 

 year, in which a person wanted to add some words to a bond which 

 had been originally written with very pale ink ; as the added words 

 were written in much darker ink, he had to go over the original 

 writing to make it look alike. Examination with the Microscope, 

 however, at once showed where this had been done. 



The Chairman said that any one who examined Dr. Maddox's 

 photographs would see that the marks of the graphite were perfectly 

 plain, and there could be no doubt about them ; but, as a rule, he 

 confessed that he was not a great believer in the evidence afforded by 

 the Microscope in cases of forgery. So far as his experience went, 

 he thought that the results obtained in this way were by no means so 

 reliable as could be desired. 



Mr. Bennett said that when he attended the meeting of the 

 American Society of Microscopists at Eochester as a deputation from 

 their Society, several papers were read on this subject, and he believed 

 that the general opinions then expressed agreed with that just given 

 by the Chairman. 



Dr. E. Crookshank read a paper " On the Cultivation of Bacteria," 

 which he illustrated by numerous drawings, and by a series of pre- 

 parations exhibited under Microscopes. He also exhibited and 

 described a collection of apparatus of the latest and most approved 

 construction for the cultivation of bacteria and for the preparation of 

 the media employed. (Supra, p. 25.) 



Dr. Maddox felt sure that all present must have listened with 

 great pleasure to the very interesting paper which they had just 

 beard. With regard to the paper process, Dr. Miquel, of Paris, had 

 pointed out that there was a certain objection to Koch's method in 

 the cases of those organisms which required a long time for their 

 growth, some of which it was known did not develop for at least twenty 

 days, during which time it was most probable they would be over- 

 spread by organisms, and consequently the original cultivation would 

 be lost. Dr. Hesse's arrangement for drawing air through a tube was 

 one which he thought they would recognize. Many of the Fellows 

 would recollect that some time ago be exhibited at one of their 



