188 JOURNAL OF THE [July, 



pean investigators, and he has studied the Diatomaces with 

 special care and distinguished success ; and it is interesting to 

 note that the results of his studies confirm the results of re- 

 searches made in the same field in our own country. If we ex- 

 amine these photographs of Dr. Van Heurck, we shall find that 

 they have a larger intention than to show the particular appear- 

 ance of any one diatom ; they bear upon the general question 

 of the structure of the diatom shell." 

 * 



CHAPMAN S MOULD FOR MICROSCOPICAL CELLS. 



The Chapman Mould, which was exhibited by Mr. E. B. 

 Grove, is a convenient implement for making cells out of such 

 plastic material as shel-lac, sealing-wax, or paraffine. It consists 

 of a cylindrical core, and a reniovable collar concentric with 

 it — both of brass. A rounded or bevelled shoulder inside the 

 collar shapes the top of the cell, and a small shoulder on the 

 core moulds a countersink suitable for the reception of the 

 cover-glass. As a single mould is intended for but one size and 

 one depth of cell, several are necessary to an outfit. 



HARD-RUBBER CELLS. 



Mr. C. F. Cox : " Excellent cells for mounting opaque ob- 

 jects may be made from hard-rubber tubes. A few years ago 

 I ordered of a manufacturing company of this city a number 

 of such tubes of the length of about one foot and of the exact 

 sizes necessary, when made into rings, to take one-half-inch, 

 five-eighths-inch, and three-fourths-inch cover-glasses. By 

 means of a -turning-lathe the tubes may be easily and evenly 

 cut into cells of any desired depth. My tubing cost only a 

 few dollars, but I have from it a supply of cells sufficient, 

 probably, to last my lifetime." 



ADDRESS ON CERTAIN SO-CALLED PRODIGIES. 



Mr. C. F. Cox addressed the Society on the subject of the prodi- 

 gies, so-called, of ancient and mediaeval times, and showed the 

 indebtedness of science to the microscope for an explanation of 

 many of them. The Address is published in full in this 

 Number of the Journal. 



Mr. J. D. Hyatt said : " In a place where I once passed the 

 summer a phenomenon occurred which created much excite- 

 ment, The surface of a considerable body of water that had 



