The Mickoscope. 175 



If after using a number of times the developer precipitates, 

 filter before reusing. In developing place the plate in a covered 

 dish, and flow on enough of the solution to cover it. This may now 

 be put aside for several minutes, while other work is being done, 

 with no fear of over-development. 



Army National Museum, Washington, D. C. 



THIN SECTIONS. 



C. H. STOWELL. 



Tt will be a fortunate day for all workers when they see the edi- 

 torial in the May number of this journal on the proper thick- 

 ness of microscopical sections. 



The first question we used to hear asked about a microscope 

 was, how much does it magnify ? but now it is, what will it show ? 



Here is a great advance, surely. We do not care to have an 

 object look large simj)ly for the sake of seeing a large object. 

 Workers have awakened to the fact that the enormous " Centen- 

 nial " and " International " stands are not absolutely necessary for 

 good resolution. They appear to have most value when exhibited to 

 an astonished jury as a most wonderful instrument, " with which 

 one can tell the blood of a woman from that of a man." 



But it is to be feared we are not making advance on the ques- 

 tion of section cutting. A recent writer says that all sections should 

 be only as thick as a single layer of its elements; meaning, we 

 should take it, that the thickness of any section should be no greater 

 than the thickness of a single cell. 



I have some sections of lung so thin they show scarcely anything 

 at all; yet it is my opinion that they are far from being as thin as 

 the 1-4000 of an inch. 



Sections of skin cut in this way are of but little value; and thus 

 we might go on, but our desire is to simply add our testimony ta 

 the list. 



With the modern microtomes, it cannot be regarded as any 

 great skill to cut these fancy sections; while it does take a fair 

 amount of technical knowledge to properly interpret what is in the 

 field. 



The advance in this line will be, not the question " how thin is 

 your section?" but rather "what will your section show?" 

 Ann Aeboe, Mich. 



