34 T. C. WHITE ON INSECT DISSECTION. 



region of the medical theatre and the dissecting-room, that none but 

 "doctors," especially educated for such researches, are capable of 

 mastering the difficulties of their details ; but that feeling is a mis- 

 take, and the sooner it is dissipated the sooner will the clear light 

 and joy of a new field of investigation be opened up for your delec- 

 tation. 



With these few words of encouragement, I will proceed to say 

 something relative to the practical carrying out of the subject under 

 consideration. 



Three things will be found necessary, viz., magnifying power, good 

 light, and instruments, and we will treat of these in this order : — ■ 



All who have seen the dissections made by our friend and fellow 

 member, Mr. W. T. Loy, must have admired the skill and neatness 

 with which they were done, and could only regret that he had not in 

 many more instances carried them on to the isolation of the separate 

 organs of each insect, for no member seems to possess greater opera- 

 tive delicacy than he. By his kindness I had an opportunity of in- 

 specting a very ingenious method of adapting his magnifying power 

 to his work, which I should like to describe to you, although I have 

 not his permission for so doing : it struck me by its simplicity, as 

 well as by its efficacy, and therefore I trust I may be allowed to 

 mention it without incurring the character of revealing any private 

 affair. It consists of a heavy metal foot, into which an upright iron 

 rod is fixed— round this rod is coiled one end of a stout wire, the 

 other end of the wire being bent into a ring to hold a watchmaker's 

 eye-glass; this arrangement, by pressing the head down, focussesthe 

 lens upon the work while both hands are at liberty, and when I tell 

 you that all these beautiful dissections of his were accomplished by 

 such a contrivance, it will be sufficiently recommended to your use, 

 even if we leave out of consideration its comparative cheapness, com- 

 pared with other optical arrangements. 



The dissecting microscope I made for my own use some years ago is 

 more complete than that I have just described, and would, if made by 

 an instrument maker, be more expensive than that of Mr. Loy. It 

 consists of a rod sliding within a tube, and made to stop at any ele- 

 vation by a fiat spring attached to it and pressing against the inside 

 of the tube. The tube screws into a hole in the dissecting table, 

 and the upper end of the rod is made small enough to be inserted 

 into the hole in the handle of the ordinary three-glass pocket lens ; 

 by this means each of the three lenses may be used as occasion 



