152 



THE AMERICAN MONTHLY 



[August, 



262. Wedl. Ueber Orseille als 



Tinctious mittel fur Gewebe. 



Archiv. f. pathol. Anat., 



Ixxiv, 143. 



Recommends the dyestuft^ of Ro- 



cella tinctoria and other lichens. 



Making Cells. 



I observe your notice of the Postal 

 Club in the March Journal. I have 

 had some experience in the use of 

 wax circles, and brass rings for cells. 

 I cut the wax rings from sheet wax 

 with Beck's improved brass punch, 

 moistening same with starch pre- 

 pared as for laundry use. To secure 

 them, clean the glass slip thoroughly, 

 being careful not to touch the central 

 face with the fingers. King's amber 

 cement, as recommended by Hei"V'ey 

 in • Behren's Guide,' is an excellent 

 cement. Lay on a ring of cement, 

 centre the wax cell in it, and as soon 

 as it will so remain, cover the wax 

 cell entirely with a layer of cement. 

 Now gently warm the whole, until 

 the wax cell settles close to slide, 

 when all air will escape. Then lay 

 aside to harden. Some experience 

 will soon make this an easy manipu- 

 lation. The edges of the wax cell 

 will be rounded, and the entire cell, 

 sides, bottom and top, will be coated 

 with the cement. I then lay them 

 aside to cure. This results in two or 

 three weeks. The longer the better. 

 I keep mine three months. The wax 

 should be dried between sheets of 

 paper before the cells are cut. 



In using brass cells, cleanliness of 

 the slide is simply imperative. Lay 

 on a ring of the amber cement, then 

 centre the brass ring in it. Allow it 

 to dry, or firmly set. Then run a 

 heavy ring upon and against the out- 

 side of brass ring, and neatly round 

 it, or pile it, with a knife blade. 

 When thoroughly dry, the ring is se- 

 cvn-e. King's ' Lacquer cell and 

 Finish ' may be used in place of the 

 amber, or as a finish. Nothing can 

 be finer. 



Eugene Pinckney. 



Photo-Micrography Without a 

 Camera. 



I have read your articles on photo- 

 micrography with a good deal of 

 pleasure, but there is one point on 

 which I wish to present a few words. 

 You say, in speaking of the method 

 w^ithout a camera, that ' it involves 

 considerable expense.' It seems to 

 me that we cannot increase the ex- 

 pense by dispensing with the camera 

 bellows, which is al"ways one of the 

 most expensive parts of the outfit 



Again, by working in a dark room 

 we can also dispense ^vith a light- 

 tight plate-holder, the simplest form 

 of holder being perfectly satisfactory. 

 The only extra expenses possible are 

 to provide some means for darkening 

 the room in the dav-time. which may 

 be done with very cheap curtains, and 

 to provide a cloth hood to extend from 

 the body of the microscope to the 

 stage, and a cap or diaphragm for the 

 lamp or lantern. I have tried both 

 methods, with and without a camera, 

 and I think the latter has some advan- 

 tages. The apparatus that I have 

 been using was constructed almost 

 entirely by myself, at an expense of 

 but a few dollars, less than the camera 

 alone for the other method would 

 cost. Although mv apparatus is 

 somewhat rough, it is quite satis- 

 factory. 



Some of the advantages of this 

 method are, that I am not limited by 

 the length of the bellows but I can 

 place the plate-holder at any distance 

 from the microscope up to five feet. 

 The apparatus might be made much 

 longer if it is thought desirable. I can 

 use the coarse adjustment with greater 

 ease bv this method. I can stand by 

 the microscope and focus on the 

 ground glass, or on a card, quite ac- 

 curatelv. Replacing the ground glass 

 or the card bv plain glass, I can make 

 the more accurate adjustment by the 

 method adopted by Mr. W. H. 

 Walmsley and others. 



As I have said, the plate-holder is 

 very simple, and one can be fitted to 

 use very large plates at a very small 



