The President" s Address. By the Bev. W. H. Bollinger. 193 



Swan, my ideas were carried out by Messrs. Elliott Bros., of this city, 

 who, early in 1879, furnished me with an apparatus that completely met 

 my want. 



The ingenious device of Prof. Schafer for maintaining a constant 

 temperature in a warm stage for the Microscope, published in 1874,* 

 formed the foundation of my arrangement. 



A drawing of the apparatus is given in fig. 31. A A is a large 



Fig. 31. 



strong copper vessel with a jacket of felt, containing water. In the 

 drawing the nearest side is supposed to be removed to show the interior. 

 B B B are three vessels containing the putrefactive fluids and organisms. 



* Quart. Journ. Micr. Sci., xiv. (1874) p. 394. 



