268 M. C. COOKE ON BLACK MOULDS. 



the glass independently, or in defiance of the little glycerine which 

 will always hang about the covering glass or the slide. This is 

 worthy of consideration, since, in most instances, cements will roll 

 up and retreat before the slightest smear of glycerine, and their 

 success depends so largely on the practically rare condition of the 

 glass being chemically clean. 



The mechanical details being now disposed of, some suggestions 

 as to the application of the objects obtained for the purposes of sys- 

 tematic study may not be out of place. Your work does not end 

 with fifty new objects mounted, catalogued, and placed in the cabinet. 

 Thus far it has been mechanical ; one man may pride himself on 

 being a better mechanic than another, but still only a mechanic, he 

 has made his tools, he has prepared his materials, but until he brings 

 these under the control of his intellect, they remain as unused tools, 

 as unemployed material. 



No longer a boy, but with a quarter of a century of experience at 

 close microscopical work, I may be permitted a little of the garrulity 

 of age, and to assume the privilege of advising younger men. Forty 

 years ago I purchased my first microscope as a scientific toy, with 

 my boyish coppers. Had it continued a mere toy it would have been 

 thrown aside long ago. This leads me to a subject which has more 

 than once been urged in this place, and must, at the risk of repetition, 

 be urged again. What are we doing with the marvellous instru- 

 ment which has been placed in our hands, for the instruction of our- 

 selves and the progress of the age in which we live ? 



To answer this question, each for himself, leads us to the reflec- 

 tion what are the uses of the microscope, and we find practically that 

 they are two, that of a toy and of a tool. A child is pleased with 

 a watch; he hears it tick, and, in his estimation, that is the perfec- 

 tion of a watch, he will amuse his fellows with it, and the faster the 

 hands will go round the better he likes it, but above all its 

 manifestation of power will delight him, there is a mystery which 

 he cannot comprehend involved in the constant tick, tick, tick ! The 

 matured child has no less respect for the watch, but for a different 

 reason — to him it is no longer a toy, but an instrument, a servant, a 

 power, a tool. By means of it his business affairs are regulated, his 

 minutes economised, and its tick serves him in counting the pulsa- 

 tions of the sick and dying, and may aid in countless ways for 

 human good. 



Is there no analogy between the watch and other scientific instru- 



