The Microscope. 247 



should attempt to have our reagents as mild and innocuous as can be 

 obtained, and their effects carefully studied before we draw conclu- 

 sions as to the structure of the objects examined. 



Trite as this may seem, it is, we think, often lost sight of by 

 investigators, some of whom stand high in authority. Methods of 

 preparation have been proposed for the brilliancy rather than for the 

 correctness of their results; and examples are not wanting where, it 

 would seem, a preconceived idea of structure had been forced to a 

 demonstration. 



As evidence for the truth of the former statement, it is only nec- 

 essary to review the class of work being done to-day. Many are 

 engaged in overhauling old methods and proposing new ones, for the 

 reason that the older methods, though often giving more brilliant 

 results, do not give correct ones. As an example, new hardening 

 agents are coming into use. Alcohol and chromic acid and its salts 

 are being displaced by materials which will not alter, though they 

 may not harden the tissues so well. All this means more patience 

 and care, and, in the end, less pretty though more truthful results. 



In the latter case examples are rare. We shall, however, give 

 one in explanation of our meaning, i. e.. Prof. Bottcher's method of 

 demonstrating a nucleus in the mammalian red blood-corpuscle. The 

 method is this: One volume of blood is mixed with fifty volumes of 

 a saturated solution of corrosive sublimate in 96 per cent, alcohol. 

 This is left, with an occasional stirring, for twenty-four hours. The 

 corpuscles are thus bleached and preserved. After settling, the fluid 

 is poui'ed off and replaced with pure alcohol. In another twenty- 

 four hours the alcohol is replaced with distilled water. The corpus- 

 cles, which have managed to preserve their identity after such an 

 ordeal, are then stained with eosin or picric acid, and mounted. 



It requires no skill to predict that when these exceedingly deli- 

 cate and soft little bodies are treated to a prolonged bath in a sat- 

 urated solution of corrosive sublimate in alcohol, something must 

 happen, and it is a wonder to us that this something should be 

 claimed as an originally structural part of the corpuscle. 



In short, oui- efPorts should be in the direction of truthful rather 

 than beautiful specimens, although a happy combination of truth and 

 beauty is not impossible. But the amateur thrives in every commu- 

 nity who makes or buys slides because they are beautiful. How 

 often one hears of a specimen: "How beautifully it shows this or 

 that," when it may do nothing of the sort. The question should 

 alwaysarise in the mind of the observer: "How beautiful the 

 structure as thus prepared, but is it naturally so ? " 



