1884-85.] 



Edinburgh Naturalists'' Field Club. 



261 



knife slides in the usual manner. The knife is not shown in the 

 fiji;ure. The microtome shown in fig. 2 is designed for objects 

 which are imbedded in paratiin or other medium previous to cut- 

 ting. The instrument consists of the usual cylinder, piston, and 



Fig. 2. 



screw — the novel point in its construction being, that tlie upper 

 part on which the section-knife slides is provided with glass rails 

 similar to those used in the Catlicart microtome, and that the 

 instrument is made to be fixed to the table by a separate clamp, 

 and not by means of a screw which presses one part of the micro- 

 tome from the other when binding it to its support. 



At the third meeting (9th January 1885) a lecture was delivered 

 by Mr A. N. Mac Alpine, B.Sc, on " The Woody Tissue of Plants : 

 its Arrangement in Root, Stem, and Leaf, and its Detection" — the 

 lecture being illustrated by the lantern. At the fourth meeting 

 (5th February 1885) Mr Alexander Frazer drew the attention of 

 members to the construction of Brooke's double nose-piece for the 

 microscope, and explained the adjustment of the same ; while Mr 

 A. D. Richardson gave a demonstration on double-staining, which 

 was much appreciated by the members, and furnished matter for 

 some discussion. At the fifth meeting (6th March 1885) a further 

 explanation of double-staining, with an exhibition of double-stained 

 objects, was made by Messrs Richardson and Henderson ; while Dr 

 Macfarlane made a communication on " Recent Advances in the 

 History of Cell-Formation." The sixth and concluding meeting 

 (6th April 1885) was occupied by a demonstration on Photo- 

 Micrography, by Mr William Forgan. The following is Mr 

 Forgan's explanation of the process : — 



PHOTO-MICROGRAPHY. 



Tlie term Photo-micrography means the production of enlarged 

 photographic pictures of microscopic objects by means of a micro- 



