PREPARATION OF OBJECTS FOR THE MICROSCOPE. 147 



or sepals of the blossom, where it cannot be supposed that they 

 ever have occasion to perform their peculiar office. But I have 

 found it very generally the case that whatever appendages the 

 leaves of a plant may have, the calyx of the flower will show 

 them in much greater beauty and abundance. 



I have said this much to explain in a measure my predilection 

 for botanical subjects for the microscope. There is no end to 

 beautiful things among them, both for artificial preparation and 

 unprepared specimens, as opaque objects. There may be beauti- 

 ful things among the preparations of animal tissues and growth, 

 but I must confess that I have never yet seen many of them. 

 Compare the plates of any animal histology, the illustration of 

 Beale's work on the Microscope, for instance, with the elaborate 

 drawing's of Sach's Botany. To use a rather gross comparison, 

 the former might remind one of a German sausage shop, the 

 latter of a French fancy store. 



Now the only way in which vegetable preparations can be 

 made available for the microscope that is, to be seen by trans- 

 mitted light is to remove the green chlorophyl, or other color- 

 ing matter, by either soaking in alcohol or immersing for a time 

 in the Labarraque fluid, which is the same as the chlorinated soda 

 sold by druggists as a disinfectant. Alcohol merely dissolves out 

 the coloring matter, leaving the cell contents, or the protoplas- 

 mic matter, still in the specimen. Therefore an object decolor- 

 ized in alcohol will be somewhat more opaque than if decolorized 

 in chlorinated soda, which destroys all the softer parts, leaving 

 only the frame work, or the cellulose. Sometimes the alkaline 

 soda in this preparation is not fully saturated or neutralized by 

 chlorine. In this case vegetable substances will be eaten up and 

 destroyed in it, as they would be in any alkali. This fact has 

 given the preparation a bad ndme with some microscopists, who 

 say that it is unsafe to use. But I have never experienced any 

 trouble in the use of that which has been made by reliable chem- 

 ists. The preparation should be kept in the dark as much as 

 possible, as light causes it to precipitate. Thin objects such as 

 ordinary leaves and thin sections will be decolorized in this solu- 

 tion in from twelve to twenty-four hours. They must then be 



