THE WOMBAT. 



GORDON COLLEGE SCIENCE CLUB, 



Annual Conversazione. 



The first annual conversazione of the science club was held 

 in the college hall on July 8th, the Rev. J. Cameron occupying - 

 the chair in the absence of the president. A collection of 

 electrical and physical apparatus — the property of the college, 

 under the charge of Messrs J. F. Dentry and Pohl, kept 

 numerous spectators deeply interested ; a series of microscopes, 

 kindly lent for the occasion by Messrs. Roebuck, Hepburn, 

 Hammerton, Grey, W. F. Dann and the Rev. W. J. Eddy, 

 furnished a great attraction to judge by the crowds round the 

 table ; in another part Mr. C. Dentry illustrated the use of 

 theharmonograph ; while an Otto air engine, lent by Mr. J. Hill, 

 kept various working models in motion; further on Mr. Battye 

 was engaged in a number of experiments in chemistry. 



The college museum showed a large and varied collection 

 of minerals, shells, birds' eggs and insects. Several models of 

 famous cathedrals were lent by Mr. W. H, Hillier, and Miss 

 Tannock kindly supplied some musical items. The best part 

 of the evening was undoubtedly the lecturette on Nansen's 

 " Farthest North." Mr. C. Dentry undertook the task 

 of explaining the slides, which were thoroughly appreciated. 

 About sixty slides were shown, and the clear explanations 

 were much appreciated. The lantern was managed by Messrs. 

 Brinsmead and Mockridge. 



THE CHEMISTRY OF PHOTOGRAPHY. 



By J. F. Dentry. 



Read before the Go" don College A. P. A., 8/4/97. 



This lecturette is given with the object of simplifying the 

 subject so that it may be understood by the lay mind, and not 

 as a scientific exposition for criticism by a professorial board. 



In order to understand the chemistry of photography it 

 is necessary to have a slight knowledge of the relations 

 existing between heat and light and their chemical action. 

 Heat is defined as a certain kind of vibration of the molecules 

 of a substance, and the relation between heat and light may 

 be briefly described as follows. When a piece of iron is 

 heated to a certain degree it emits red light, but if raised to a 

 much higher temperature it emits white light ; red light may 

 therefore be said to represent a low heat, or a small amount 

 of energy, while white light represents a large amount of 



