THE METHODS OF MOUNTING MICROBES 83 



marked that nearly all microbes can be stained 

 with the various aniline dyes ; although their 

 capacity for absorbing these dyes differs consider- 

 ably. This capacity or affinity for aniline dyes is 

 of great use to the bacteriologist to ascertain the 

 presence of microbes, and to differentiate in many 

 instances morphological details which in the un- 

 stained condition are not discernible. 



Hardening, Imbedding, Cutting, and Mounting 

 Preparations. Many medical men and students on 

 reading the different staining, hardening, imbedding, 

 cutting, and mounting processes ' which any tissue 

 has to undergo before it can be examined with 

 the microscope, will be inclined to think it very 

 tedious work. It is, however, a mere matter of 

 routine, and when once this routine is established, 

 the whole thing is comparatively simple. It takes 

 very little time to change the hardening fluid, and if 

 the student gets into the habit of looking over the 

 bottles on the shelf every morning where he keeps 

 tissues in the process of hardening, a glance at the 

 labels will show those requiring a change. When 

 the sections are mounted and examined under the 

 microscope, he will find himself amply repaid for 

 all his trouble if he has faithfully carried out the 

 different processes in every detail. It is always 

 better to have one or two shelves devoted to those 

 preparations which require changing; and those 

 which require fresh fluid often, as for instance 

 those hardening in chromic acid should be kept 

 by themselves. Each bottle should be labelled, 

 and the tissue, date, and hardening fluid clearly 



