15 



velopment ordinary type can be read with the greatest ease, so 

 that it is rather a misnomer to call the room a "dark" room. 



THE ILLUSTRATION ROOM. 



Several of the rooms of the Laboratory of the Division of 

 Pathology and Physiology are specially fitted up for the use 

 of solar projecting apparatus. This projectino- apparatus is pri- 

 marily for the purpose of projecting negatives and microscope 

 preparations from which illustrations are to be prepared, and in 

 some ways the apparatus thus used ta'kes the place of the ordi- 

 nary camera lucida, and for the class of objects to which it is 

 suitable, it affords many advantages over the camera lucida. It 

 is however limited in its application so far as the microscope is 

 concerned a:s it is impossible to use the highest powers of the 

 microscope in this manner. A second use to which the projector 

 will be put is the projection of images of microscopic objects 

 which are under examination and which it is desired to show 

 to- more than one person at a time to facilitate discussion and 

 study. Needless to say the projector can be used in the same ■ 

 manner as an ordinary stereopticon or magic lantern, with the 

 advantage that, as sunlight is more powerful than any artificial 

 light, much better images may be secured. It is also needless 

 to say that the instrument has the inevitable drawback that it 

 can be used only when the sun shines. 



When the instrument is used in the production of illustrations, 

 it is customary to project the negative, or preparation, upon a 

 glass screen of special character. The object of the screen is to 

 secure to the artist that freedom of movement which comes 

 from relieving him of the drawback which is usually presented 

 by. the shadow of his own hand and person. The projector 

 has often been used for the production of illustrations, but 

 the writer is not aware that the present method has been 

 hitherto exploited, except in his own private laboratory, 

 namely: the use of so^ powerful a light as to enable the operator 

 to throw the image through ordinary cartridge paper, thus en- 

 abling him to work on what may be called the backside of the 

 projection. This method is an expeditious one and is a very 

 great gain indeed from an artistic point of view. It is a gain from 

 almost any point of view, but it particularly gives a freedom oF 

 treatment that has to be experienced to be fully understood. It 

 is found that the projector when used in this way facilitates the 

 production of illustrations from negatives so poor that they 

 would not make a print suitable for reproduction by the half- 

 tone or any other process. Furthel-more, it often happens that 



