72 The Microscope. 



designed to use, I contrived wa}^ of my own which proved, 

 however, to coincide essentially with theirs. The operations are 

 very simple. 



Two pieces are taken from each carcass just after it is 

 "dressed" — one from the muscle called the "pillar of the dia- 

 phragm," and the other from the psoas muscle (tenderloin). 

 Tags are provided with duplicate numbers, one of which is at- 

 tached to the hog by a barbed staple, and the mate is put with 

 the pieces of meat in a little box, and these boxes in tin cases 

 provided with combination locks to preclude the possibility of 

 the samples being tampered with when left over night in the 

 cooling room. The microscopist's work is as follows : Three 

 small pieces are snipped with scissors from each piece, length- 

 wise to the fibre, and these pieces being laid on a slide of thick 

 plate glass (3x2 and nearly J inch thick) are moistened with 

 water from a medicine dropper, and another similar glass plate 

 being superposed, the two are pressed and rubbed together with 

 a rolling motion, which suffices to disintegrate the bundles of 

 fibres without tearin-;; with needles. A preparation is thus made 

 in less than two minutes, which is quite translucent — a single 

 layer of muscle fibre in fact. It is better to take half a dozen 

 small pieces, which will fairly cover the slide when pressed out, 

 than to spend time tearing out thicker pieces. These slides I 

 examined directly, keeping them pressed together with the 

 fingers, but the Bureau officials provide a compresser of two 

 frame pieces screwed together as shown in the figure. It seemed 

 at first that such screw pressure would be needed effectively to 

 compress the fibre, but a single trial convinced us that our old 

 way was the better, and the compressors were used here only as 

 convenient for passing around the preparation for reinspection, 

 and by some to save wiping off" the glasses as carefully as is re- 

 quired when they are used alone, as the least moisture causes 

 them to adhere to the stage. 



The microscope provided by the Government is one of the 

 Bausch & Lomb Optical Co.'s make — their " Model " stand, with 

 a large square stage, a f objective, affording a magnifying power 

 of about 60 diameters, with tube down. I prefer to work with 

 a lower power; an inch or even a IJ inch objective answers, I 

 find, and affords more light. This system taxes the eyes less, 



