189I.] NEW-YORK MICROSCOPICAL SOCIETY. 105 



One thing I have omitted to mention which is of interest. Mi- 

 croscopic crystals are seldom found in clear, straight, laminated 

 mica. They are much more likely to occur in mica which I 

 should describe as crinkled. The piece of mica enclosed in the 

 paper, marked "A," will explain my meaning. I think there are 

 seven separate and distinct crystals in this piece. At one place 

 three fan-shaped crystals can be brought within the field of my 

 one-inch objective, although when the three are seen they will all 

 be well toward the outer limit of the field. 



A brief description of my method of getting my specimens ready 

 to mount maybe of interest. Having discovered a crystal by ex- 

 amining the piece of mica in a strong light, and by the aid of a 

 hand-glass of two to three inches focus, I endeavor to remove the 

 mica, layer by layer, until I have lifted off the last continuous 

 covering layer, then to do nearly the same thing from the other 

 side until I have removed all but the last layer. This can be 

 done quite easily by cutting, out, with the scissors, a square with 

 the crystal about in the centre. Mounting upon a slide is quite 

 simple when the specimen is thus made ready. I have had better 

 success with Canada balsam than with glycerin jelly, but there 

 may be better media with which I am not acquainted. My meth- 

 ods are the methods of twenty-five years ago, as I have hardly 

 looked through a microscope till I found the microscopic Tour- 

 malines, and, being a busy man, 1 have had no time to give to it, 

 excepting in the evening, generally after nine o'clock. 



Hoping I may have been enabled to bring to your notice some- 

 thing before unknown, and which may give you pleasure, and ask- 

 ing your kind indulgence for my slides, which I am aware are 

 faulty in preparation, 



I am, very truly, 



Your obedient servant, 



Edwin S. Drake. 

 Portland, Maine, January 13th, 1891. 



