1897 THE MICROSCOPE. 93 
and seeks to master it. No one can be great in all 
branches. All love to know a little about everything. A 
nice little book to start a student on his way is ‘“‘A Guide 
to the Microscopical Examination of Drinking Water,” by 
J. C. McDonald, M. D., published by P. Blakeston & Son 
& Co., Philadelphia. 
Hands Off.— When exhibiting the wonders of your 
instrument to the uninitiated, they are very apt to grasp 
the tube while looking through. Never fail to protest. 
This grasping is utterly unnecessary and it positively 
destroyes the lacquer. It, after much handling, will look 
as if it had had the small pox; the bright golden polish 
which is produced by lacquer can easily be tarnished. 
QUESTIONS ANSWERED. 
Nore.—Dr. S. G. Shanks, of Albany, N Y., kindly consents to receive al. sorts of ques- 
tiens relating to microscopy, whether asked by professionals or amateurs. Persons of at. 
€ ades of experience, from the beginner upward, are welcome to the benefits of this depart- 
ment. The questions are numbered for future reference. 
Q. 252.—Kindly advise me. What ts the retail price of Fresh- 
Water Sponges by Edward Potts? B. W. 
A.—It can be had from Queen & Co., of Philadelphia and 
costs $1.56 postage paid. It is a reprint from the Proceed- 
ings of the Academy of Natural Sciences, Philadelphia, Pa., 
1887. 
Q. 253.— What ts the address of Edward Potts ? 
A.—We do not know. Can any subscriber tell ? 
SCPENGE-GOSS le. 
Royal Microscopical Soctety. 
Mr. F. Enoch, showed under the microscope a unique 
collection of specimens ofa ‘‘much-neglected family”’—viz., 
the mymarade. ‘These insects, some of them much tin- 
ier than a grain of sand are egg parasites, that is to say 
