74 THE MICROSCOPE. May 



without bulk staiu, also iu dilute alcohol and formalin. 

 We concluded that the rapidity and less shrinkage were 

 alone sufBeient to recommend the use of the new agent. 



Mr. J. H. McGrregor, who was conducting an investi- 

 gation of the central liervous system oi Cryptohranchus 

 in the same laboratory, used the agent in combination 

 with alcohol and other agents to his entire satisfaction. 

 He will doubtless give his results when his paper is 

 printed. Another student used it successfully in prepar- 

 ing the eyes. 



I may say, in short, that the result of the few months 

 of trial warrant a high estimate of it for fixing animal 

 tissues. 



Care of the Eyes. — In the earlier use of the microscope 

 the care of l^he eyes cannot be too persistently urg-ed. The 

 wrecks of those wonderful org-ans along- the shores of mi- 

 croscopy are too numerous to be ignored, or their lessons 

 unheeded. Many more which have beg-un without rules 

 have reluctantly abandoned the fascinating use of the in- 

 strument before utter instruction, but with impaired vis- 

 ion who, had they been governed from the first by the fol- 

 lowing hints, might have made comparatively weak eyes 

 strong, and attained eminence in this pivotal, key-note, 

 science and art. 



(1.) Begin exclusively with yourlowest powerobjective. 



(2.) Until self-mastered use but one object at a sitting. 



(3.) Lengthen the time only live minutes at each sitting. 



(4.) Never begin work heated, angry, or greatlyexcited. 



(5.) Stop instantly at the iirst scratchy-feeling in the 

 eyes. 



(6.) When two hours is not weary, you arc safely ini- 

 tiated. 



Now use the next hig-her power objective under the same 

 rules, hall" of thesittingtime at each sitting, and thus on, on, 

 on, as necessity, or inclination beguiles or commands. 

 "Excelsior, excelsior." 



