THE Microscope. 171 
ple, a Pediastrum tetrus or small Cosmarium under the higher 
power, I turn on the 1 in. (a nose piece is indispensable), run 
back, remove the small speck and place him in the little pool 
containing his brethren that have gone before him. Docidiums 
and long strings of filamentous Desmids are safely taken up by 
holding the tube in the direction of their length and expelling 
them with tube held nearly horizontal to avoid injury from 
flexure. A very little experience will enable the beginner to 
transfer with certainty, ease and rapidity any object he can 
make out under 250.500 diameters. Itis a pleasure to find, on 
running down again with high power, the field undisturbed in 
relative position of objects except. that the one desired is miss- 
ing. 
This method is of course equally applicable to separating 
Diatoms or any minute objects which it may be desirable to 
preserve. Mosses, etc., too large to enter tubes can be sucked 
against their ends and there held while being transferred. 
Further, in microchemistry, minute erystals can be taken up 
from plant sections, moved to a clean portion of the slide (or 
better to a piece of thin (cover) glass held in a match stick han- 
dle which admits the application of heat when needed) and then 
treated with solvents, etc. For the use of re-agents. in order to 
avoid the undue multiplication of tubes and the contamination 
which would result from using the same tube for more than one 
re-agent, I use little test-points—formed by drawing out small 
glass tubing—with bulging body and short tapering shank which 
is inserted in a small hole passing through a cork stopper which 
closes a glass tube (3 in. x 5-16) the other end of which is drawn 
out and cut off to admit of substitution for a fishing tube. These 
points are kept on a convenient tray or large watch glass and 
being charged with various liquids permit the ready and per- 
fectly controlable application of any test or stain to very small 
quantities of matter. Precipitates can be formed, re-disolved, 
etc. 
The Desmid tubes, test-points, etc., can be fashioned by 
any one, after a few minutes practice, from small glass tubing 
by aid of the blow pipe. A common kerosene lamp furnishes a 
good enough flame for the purpose. To prevent blackening of 
tubing (containing lead) it must be kept out of the inner, lumin- 
ous reducing flame. 
