1901) MICROSCOPICAL JOURNAL. 225 
sufficient lampblack to make a good black fluid ; this may 
be used with a steel pen for writing on a cover glass or 
slide, after which the glass should be held over a flame 
until the characters are dry; glasses so treated will not 
lose identification marks if placed in solutions. 
Puoto-MicRoGRAPHY.—Workers with limited means | 
are often tempted to try this process but are appalled by 
the number of fittings usually specified as necessary. It 
has to be borne in mind that not everyone is bent on per- 
forming feats of resolution of diatoms or working with 
high powers. In making observations, there are numer- 
ous enthusiastic amateurs, who, seeing a striking feature 
in an object, desire to record the appearances by photo- 
graphing it for future reference. or for the edification of 
friends. The majority of such work would come within 
the scope of 1” or 3” objectives, and many of the ordi- 
nary fittings of complete photo-micrographic cameras are 
not really necessary, however desirable they may be. 
What is the simplest apparatus that can be used ? 
Being provided with a microscope and bull’s eye, the 
additional apparatus would consist of a lamp,some form 
of camera, a support will carry the camera at the axis 
height of the microscope when set horizontally, and a 
tube to connect the front of the camera with the body of 
the microscope. | 
1. The Lamp.—This need not be of an expensive kind 
such as is ordinarily supplied for microsopical work. One 
with a tin frame which is purchasable at an oil shop for 
25 cents answers very well. 2. The Camera.—This should 
have not less than 10” of extension and requires to have 
a good dark slide with it. The focussing would, of 
course, be done by means of the microscope adjustments. 
3. The connecting tube might be of cardboard or of brass 
as preferred. 4. A support for the Camera.—This is 
really of great importance in an arrangement of this 
kind. It would be well that a frame should be shaped 
