1886.] 



MICEOSCOPICAL JOUENAL. 



be stopped with a ' cork, whilst the 

 ^vide-niouthed ones may be sealed by 

 the blow-pipe, oi" if tubes are to be 

 cleaned by immersion in acid, etc., 

 all may be thus sealed. 



An equally good, perhaps better, 

 way to secure a pipette with all re- 

 quired advantages is as follows : Take 

 a proper piece of large rubber tubing, 

 e. ^. , 3 inches long with half or three- 

 fourths inch bore, and two short rub- 

 ber corks to fit ; pass the tube through 

 one stopper and into the other ; drill a 

 hole in the glass-tube near the upper 

 one, and bring all to place. This form 

 works promptly, is durable, and has 

 one advantage, when laid on the \vork- 

 table the point is free from the same 

 so it does not gather dust. 



I am aware there is little new mi- 

 croscopical apparatus to be devised 

 under the sun, so many mav be using 

 similar or equallv good pipettes, none 

 use better and manv use poorer. 

 These may act on the above sugges- 

 tions and make for themselves the 

 best. 



Photo-Micrography. — III. 



BY THE EDITOR. 



3. Apparatus (continued). 



Microscope and accessories^ 



b. 



camera^ etc. 



As regards the microscope stand, 

 but little need be said, since any 

 good stand will serve perfectly well. 

 There is an advantage, however, in 

 a large body-tube, particularly for 

 work without an eye-piece. A me- 

 chanical stage is desirable, and a 

 sub-stage also. 



In arranging the microscope for 

 photo-micrography the bod}'-tube 

 should be lined with dead-black 

 cloth, to avoid reflections. If the 

 ocular is not to be used, remove the 

 draw-tube, and prepare a lining for 

 the body-tvibe as follows : — Choose 

 some rather heavy, smooth paper, and 

 a strip of black cloth as long as the 

 body-tube and wide enough to line 

 it, the edges overlapping by half an 

 inch, more or less. Paste the cloth 



on one end of the strip of paper, 

 and let it dry. Then make a roll, 

 the cloth inside, and fit it in the tube. 

 Apply some mucilage at the end 

 which, when dry, will maintain. the 

 paper tube of the proper size, re- 

 move it from the body-tube and ap- 

 ply mucilage along the entire length. 

 The tube is then ready for use. In 

 this wa}' we have made many a pa- 

 per tube, which has more than 

 served its time for its intended pur- 

 pose. By rolling several thicknesses 

 of paper, thickly coated with mucil- 

 age, together, very strong and ser- 

 viceable tubes can be made, which 

 may serve as draw-tubes, fittings for 

 accessories, etc. 



We now come to the question 

 whether or not oculars shall be used. 

 In the one case the camera may be 

 verv short, since the image is magni- 

 fied rapidly b}' the very divergent rays 

 from the ocular as we recede from it. 

 In the other case the magnification is 

 obtained by increasing the length of 

 the camera, taking the more slightly 

 divergent rays directly from the ob- 

 jective, sometimes interposing an 

 amplifier to increase the power, or 

 to improve the definition. 



Having seen excellent results from 

 both methods, we are not disposed to 

 express a very decided opinion 

 against the use of the ocular, al- 

 though strongly disposed to favor the 

 other plan. The reasons for this 

 may be briefly stated. In the first 

 place, none of the photo-micrographs 

 produced with the ocular that we 

 have seen have been of a nature that 

 would test the highest capabilities of 

 an objective. It is true, we have 

 seen photographs of the Avi phi- 

 pleura pellucid a taken in this way, 

 but in such cases the field of view 

 has invariably been very small, only 

 a portion of the frustule being 

 shown, so that it would be impossi- 

 ble to judge of the definition over a 

 larger field, such as would be ob- 

 tained with the same magnification 

 without the ocular. It is scarcely to 

 be expected that the widely diver- 



