THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL 



Vol. hi. 



ITew York, June, 1882. 



No. 6. 



Glass Cells. 



BY C. HENRY KAIN. 



Much has been said and written 

 within the past year or two in regard 

 to the proper material for cells, but in 

 all the discussion I have noticed that 

 very little mention is made of glass 

 cells. For many purposes, especially 

 for balsam or liquid mounts, they are 

 preferable to all others, but their 

 cost prevents their general use — a 

 dollar a dozen being the usual price. 

 I think if microscopists in general 

 knew how easily they can be punched 

 from glass covers, they would come 

 into almost universal favor for shal- 

 low mounts. Their cost is trifling, as 

 the cheaper grades of covers can be 

 used, also those which v/ould other- 

 wise be thrown aside on account of 

 some flaw or impurity in the centre. 



The following is the method of 

 preparation : Take a brass plate, say 

 five inches long, one inch wide, and a 

 quarter of an inch thick. Have a 

 number of holes drilled (not punched) 

 in it about an inch apart, and of vari- 

 ous diameters corresponding to the 

 diameters of the desired cells. See 

 that in drilling these holes the shoul- 

 ders are left perfectly square and 

 sharp, but not burred. This is im- 

 portant, as the question of success or 

 failure largely depends upon it. The 

 plate having been thus prepared, heat 

 it until it is sufficiently hot to melt a 

 piece of sheet-wax placed upon it. 

 Then place over each hole a disk of 

 sheet-wax somewhat larger than the 

 hole, and drop upon it a glass cover. 

 The cover should be from -^^ of an 

 inch to }( of an inch larger in di- 

 ameter than the hole. Press the 



cover down so as to bring it in close 

 contact with the metal plate, then set 

 the plates away to cool. When per- 

 fectly cold take an ordinary sixpenny 

 or eightpenny nail, boldly thrust it 

 through the glass cover from the up- 

 per side, and rasp it round and round, 

 always with a downward motion, un- 

 til the cell appears perfectly circular. 

 When all the covers upon the plate 

 have been thus treated, reheat the 

 plate so as to loosen the cells, throw 

 them into benzine to dissolve the 

 wax, let them remain a few minutes, 

 then wipe them and put them away 

 for use. 



The method given is simple, but 

 when describing it I have some- 

 times been met with an incredulous 

 smile, as the idea of punching holes 

 in glass with an ordinary eightpenny 

 nail seems so ridiculous. Neverthe- 

 less it is a successful method ; and, 

 furthermore, if the directions given 

 are carefully followed, not one cover 

 in twenty need be spoiled in the 

 process. Try it. 



[We have received some of the 

 cells made by Prof. Kain by the 

 method described above, but they 

 were broken in the mail. Judging 

 from the fragments, they were per- 

 fectly good cells for any and all pur- 

 poses. If we are not mistaken, Dr. 

 L. Beale describes a method quite 

 similar, somewhere in his book on 

 the microscope. — Ed.] 



Rotifer Nests. 



Exploring ponds in the low grounds 

 along Paxton creek, flowing through 

 the eastern suburbs of the City of 

 Harrisburgh, Pa., April 15th last, I 



