THE Microscope. gal, 
lorrespondence, 
Editor of THE MICROSCOPE: 
I have a first-class test slide of P. Angulatum mounted dry 
on thin cover glass, in black varnish cell. About a year ago 
beads of moisture appeared on the slide, which since then have 
gradually increased in size. Will they continue to do so until 
the mount is entirely ruined? If so, can anything be done to 
save it? Haroitp PLowe. 
<2 > 
Dr. STOWELL, 
Dear Sir; Isend you slide of Desmids, &e., a dip from a 
small zoophite case—no preparation, the drop was put ina cell, 
then the water was absorbed by strips of blotting paper; then 
a mixture of (carbolated) mucilage of Gum Arabic and solu- 
tion of Borax, was mixed in a watch glass, a drop put on the 
desmids, covered and ringed. My object is to call your atten- 
tion to the medium. Of course, it is a well-known fact that a 
solution of Acacia and Borax will gelatanize in a few minutes, it 
then dries up to a vitreous scale. I have never seen this sug- 
gested as a mounting medium, it is easily managed and may be 
valuable for desmids, &¢., provided it has no bleaching or shrink- 
ing property—time will decide, I see new mediums are in or- 
der. If this proves of use, I have no desire to keep it in the 
background. You may like to experiment on tissues with it. 
Try high powers on some of the empty desmids. 
The long desmids are not figured in any of the few books 
I have. Would like the name of them. Of course I have 
nothing especially beautiful about this slide,except to call your 
attention to the medium, and when it suits your convenience 
will be glad to hear from you. I have not tried it on diatoms. 
Yours truly, 
K. E. Jackson. 
———$—_—_<_<< 0 
The desmids mounted as described by Mr. Jackson show 
well at this time. 
