1869.] EDWARDS — :\[ICROSCOPE. 23 



to have as much light, and as large a field of view as possible, and 

 plenty of room upon the stage, to manipulate or dissect an object 

 laid upon it. 



The student can never be satisfied with mounted objects, he 

 must dissect a tissue, a flower, or an insect upon the stage, and 

 educate his hand to work his delicate mounted needles, (which look 

 under the powers like flag-staffs), — with the a-reatest precision and 

 nicety. This cannot readily be done with a contracted stage. 



The illumination of the object above and below the stage, in 

 the absence of costly apparatus, may be skilfully accomplished 

 provided only that the stage is thin and the aperture large. 

 Oblique light may be obtained by direct lamp light or by the 

 opaque condenser, so as to give the most delicate effects. 



Lastly, a rack work adjustment is always to be preferred to a 

 sliding one, and the opaque condenser is most useful on a separate 

 stand. 



Thoroughly worked and studied, the instrument 1 have 

 described will fulfil all the requirements of the medical student 

 and practitioner ; but the instrument implies work, study, and 

 perseverance, and is not designed to be a mere library ornament. 

 I am aware that in many English and Scotch Schools of Science, 

 German and French Microscopes are imported for the use 

 of medical students and recommended for excellence and 

 economy, and no doubt Chevalier, Oberhauser, and Nachet turn 

 out excellent work at a moderate cost. Yet I prefer the build of 

 the English instrument, especially for room upon the stage and 

 good rack movements. Dr. Lawrence Smith's inverted Micros- 

 cope as made by Nachet, is however a very excellent form of 

 working instrument, and with many useful accessories, is sold at 

 the moderate price of £14 sterling. 



Now I shall address the advanced student, the Naturalist: 

 who says perhaps " I have deferred getting a Microscope until I 

 could aff"ord a really good one, and I should like to add to a first 

 rate stand, various powers and accessories as I can afford or 

 happen to meet with them." While I sympathise with these 

 views and acknowledge that this was the plan upon which I started 

 in 1851, yet I think upon the whole it is not the wisest one, espe- 

 cially if it should delay, even for a single year, the possession of 

 an instrument which you can call your own. Not that I regret 

 it in my own case, for I regard with peculiar pleasure the big 

 baby which has grown up under my parental care for 18 years. It 



