[141] 



^be rnMcroscope in the Xecture anb 

 Classs'lRoom. 



By William Pumphrey, 



HOW to make the microscope available in the lecture and 

 class-room must often have been the unavailing desire of 

 him who has had to stand behind the lecture-table when 

 some point of insect anatomy had to be elucidated, or when a 

 class had to be instructed in the ultimate details of vegetable 

 physiology. Who has not longed for the ability to place before 

 his audience or his class exactly the point or points he desired to 

 impress upon them, and who has not felt that to do so was almost 

 an impossibility ? 



So far as the lecture -room is concerned, the microscope in its 

 ordinary form is absolutely useless. There are no means whereby 

 the occupants of the room can be made to see in the microscope, 

 at one and the same time, the object, or the special part of an ob- 

 ject, that the lecturer wishes to call their attention to. It is true that 

 at the close of the lecture the audience may be invited to examine 

 preparations illustrative of the lecture. But, then, to make this of 

 much use, the lecturer must be prepared to repeat, to a great 

 extent, what he has already explained, and this to each observer 

 and with every specimen. 



With a class of, say, a dozen students, the thing is a Httle 

 more practicable, but the business is a very onerous one, and its 

 results at best very uncertain. Perhaps, in the course of his one 

 hour's lesson, the teacher has to call special attention to, for 

 example, six preparations. In order that the class may follow the 

 lesson, and fully understand and appreciate the point intended to 

 be enforced by these preparations, it will be needful that each 

 student should have a microscope and be furnished with a prepara- 

 tion, so that he may follow the points of the teacher's lesson. 

 This, of course, involves a dozen microscopes and six dozen pre- 

 parations. But this is not all. Probably, no two of the students 

 are equal in their powers of observation, and the preparations are 

 certain to be of unequal merit ; and supposing that these causes 

 of uncertainty could be removed, the teacher has no proof that 



