170 THE MICROSCOPE AND ITS PREPARATIONS. 



The fact is, that in order to display at all the internal structure 

 and modes of growth of vegetable tissues, and the delicate 

 glands and organs which make up the vegetable economy, it is 

 necessary to make the specimens transparent by dissolving out, 

 in some way, the green chlorophyl. Alcohol will do this, but it 

 usually takes quite a long time. The chlorinated soda solution, 

 sold by druggists as a disinfectant, will do it much more effectu- 

 ally, and in a few hours time. After this operation, we have an 

 object which is certainly translucent, but the parts are of such 

 uniform brightness that they are not readily distinguishable one 

 from the other. It is necessary again to slightly color them, in 

 order to obstruct some portion of the light, and to contrast one 

 organ or tissue with another. Here comes in the art of the 

 microscopist. Without effacing a mark or destroying the faintest 

 tracing in his picture of nature's work he can give it to you in 

 oscuro, in monochrome, or in varied and contrasting colors. And 

 when you see that beauty of coloring in no wise detracts from 

 the naturalness of organs or tissues, or from the true representa- 

 tion of vegetable growth and processes, I think you will accord 

 to the enthusiast of this art, the painters' freest license. 



My friends, I have given you a brief introduction to one of 

 the most interesting of the sciences one which lies at the 

 foundation of all the natural sciences, for the microscope is now 

 the indispensable instrument in all physical research one which 

 opens up more vistas of knowledge and of exploration than any 

 other branch of experimental physics and one the merits of 

 which, I am happy to say, are being every day more appreciated. 

 I even cherish the hope to live to see the day when its claims as 

 a distinct and worthy science shall penetrate the incrusted hel- 

 mets of the heads of our learned universities when its manip- 

 ulations, its processes, and its investigations shall be considered 

 equally important teachings with the reactions of chemical 

 agents, and the work and handicraft of the laboratory. 



