178 THE MICROSCOPE. 
The metal platinum is also present in this sand, but whether 
in quantity sufficient to make it of commercial importance has not 
yet been ascertained. 
The zirconite occurs in square prisms with pyramidal termina- 
tions, and the stones are of a light-brown color and very transparent. 
Altogether, the discovery of Mr. Brainbridge is a remarkable one, 
and its future investigation will be watched with great interest. It 
might be mentioned that the sand, of which samples were shown 
last evening, extends over a space of one-half to three-quarters of a 
mile wide by several miles in length. 
Mr. Wickson exhibited a peculiar entomological phenomenon— 
the common aphis attacked by the ‘‘F ly cholera”; or, Hmpusa musce. 
The gentleman explained how the fungus spores lodge on or become 
attached to the body of a fly, immediately commence growing and 
penetrate through the skin. - Once inside, the spore rapidly increases 
by self-division, in the manner of yeast cells. The first stages of 
the disease is indicated by the restlessness of the attacked flies; they 
soon, however, become weak and slow in their motions. Having 
securely fastened themselves with their broad tongues to the object 
upon which they happened to be when attacked by the last stages of 
the disease, a succession of spasmodic tremors pass through their 
wings and legs and they stiffen themselves out to fly no more. 
The abdomen of the victim of this disease, previously already 
swollen, becomes more and more distended, and a fatty, 
whitish substance pushes through the softer membranes between 
the chitinous rings or segments. Soon after a whitish halo of 
spores is formed around the dead body, readily seen if the fly 
happens to have fastened to the glass of mirror or window-pane. 
These spores gradually cover the whole insect with a white dust, and 
they appear in ever-increasing numbers as the body of the victim 
dries up, until at last its whole interior is empty and only a shell 
remains. From an examination of the affected aphis, there appears 
no reason to doubt but what the fungus developed and ran its course 
the same as in the fly; their bodies being distended and surrounded 
with the white halo of filaments bearing ripe spores ready to be 
thrown off and carry on their work of inoculation. 
It was suggested that here might be found a remedy for these 
annoying pests, by systematically inoculating Aphis colonies when 
existing epidemically, and Mr. Wickson stated that such a course 
had been spoken of, but could not say that it had ever been carried 
out. Unfortunately, the more destructive of the fruit and grain 
pests do not seem to be seriously attacked by this fungus, although 
