The Microscope. 23 



one or two of each, and with fiendish glee smashes the rest 

 and dumps their remains into another bandbox. Glycerine, 

 Canada balsam and a weak solution of chloral are about all the 

 necessary mounting media. For cements, shellac, Brunswick 

 black, and one of King's fine preparations will answer every 

 purpose. Among the stains, hgematoxylin and eosine are useful 

 and trustworthy ; for a double stain, picro-carmine easily holds 

 first place. For the Bacillus tuberculosis, Burrill's stain is satis- 

 factory and manageable. If the microscopist is going into bac- 

 teriology he will need a laboratory, and having reached that 

 point he will be able to take care of himself. Yet even there 

 he will accumulate bandboxes, unless he be discriminating and 

 self-possessed. 



Worthless or next to worthless objectives will sometimes get 

 into the bandboxes where they become very, ver}', cumber- 

 some. For this the dealers are secondarily to be blamed, pri- 

 marily the purchaser that demands " high power," and gets it. 

 But when he gets it, he is like Miss Edgeworth's naughty little 

 girl with her blue china vase. Four poor objectives will in 

 money cost as much as two good ones, and be sixteen times more 

 useless. In the loss of educating experience and of the optical 

 tactus eruditus, the cost is greater than any money can counter- 

 balance. What the average microscopist needs is one good ob- 

 jective of low power, and one of medium hjgh power. With a 

 one-inch and a one-fifth the worker is well equipped even for 

 some original investigation. At any rate, he will have two good 

 lenses to " grow up to," and he will find that they will appear to 

 improve as he ascends to their level. If he is to go into the 

 resolution of Diatoms or into other " microscopical gymnastics," 

 he will need special apparatus, and the rest of us will look on 

 in silent awe as he searches for the " chalk marks on a white 

 wall." 



One of the writer's friends possesses this battery of objectives: 

 a variable three to five-inch, a two inch, a one-inch, a A, a ^, a ^, 

 a |- homogeneous immersion, a to homogeneous, and a ^V homo- 

 geneous. The cost was four hundred dollars, and the objectives 

 are magnificent, yet he rarely uses any but the one-inch with 

 the ^ and the ^. These are all that he needs for his work ; the 

 others are therefore trash that must fill the bandboxes, and hin- 

 der his microscopical progress, since the cost might have been 



