SCIENCE-GOSSIP. 



247 



hydrated in absolute alcohol, cleared in cedar oil, 

 and mounted in Canada balsam. The bacilli will 

 then be stained red and the surrounding tissue 

 blue.—,/. U. L. Dixon, M.R.C.8., L.ll.C.P. 



Examining Bacteria. — For the information of 

 members I give a short explanatory note on the 

 examination of bacteria. If the slide is prepared 

 for photo-micrography, gentian violet is the most 

 suitable stain. Take a drop of the bacterial solu- 

 tion on a platinum wire, and touch with it a clean 

 cover-glass that has been washed with water and 

 alcohol. Then take a second glass, rub the two 

 together so as to get a nice clear film on the 

 glasses. Then filter some fuchsine in aniline, and 

 place the cover-glasses in the pigment. Occasion- 

 ally take one out with the forceps, and if stained 

 wash well in alcohol. Now stain again in the methyl 

 blue, wash in dilute sulphuric or nitric acid, then 

 again in alcohol, and when the cover-glasses are 

 dried with a piece of filter-paper or blotting-paper 

 they can be mounted in bal- 

 , sam. It seems a tedious pro- 



! • cess, but when understood is 

 ""V J-vC,, very easy. I often examine 

 i ! ' j"' spleen for tubercle bacilli by 

 / I f this method in fifteen min- 



' utes. A splendid double 



Pig. 6. Bacillus tuber- stain can be purchased from 

 culosis in sputum, from Messrs. R. & J. Beck, of Corn- 

 photograph, hill, London, for one shilling 

 per bottle, which saves great 

 work, but the solution must be warmed before 

 use. — Jolin Swift Walker, 31. JD. 



[We gave a note on staining tubercle bacillus in 

 Science-Gossip, vol. vi. p. 247. Bacillus tuber- 

 culosis occurs in long, thin, non-motile rods, 

 straight or curved, rounded at the ends, frequently 

 beaded, as shown in the illustration, 2 microns 

 to 4 microns and occasionally 8 microns long. 

 The micron is the standard of microscopic 

 measurement, and measures one-thousandth of 

 a millimetre. It is generally represented by the 

 Greek letter /j. — Ed. Microscopy, S.-G.] 



MICROSCOPY FOR BEGINNERS. 



By P. Shillington Scalks, F.K.M.S. 

 (Continued from p. 217.) 



All slides should be carefully labelled and kept 

 in proper boxes. The boxes should contain trays, 

 so that the slides may lie flat, and these can be 

 obtained very cheaply. 



This series of papers, begun some eighteen 

 months ago, has now drawn to a close. We have 

 endeavoured throughout to keep in view the wants 

 of the beginners for whom we were writing, and to 

 give just that practical information and advice as 

 to the choice of a microscope and its accessories, 

 their uses, and the more elementary methods of 

 preparing objects for the microscope, that ex- 

 perience has taught us the beginner most needs. 

 We have tried also to explain, without techni- 

 calities, the principles underlying microscopical 

 practice, methods, and technique, "and though we 

 feel we have barely touched upon the subject, we 

 have been encouraged, by numerous letters from 

 readers hitherto unknown to us and by personal 

 expressions of interest, to believe that our— we 

 trust unassuming — efforts have been of real service. 



So much is this evident that we may add that 

 it has been decided to shortly republish these 

 papers in handy book form from the offices of this 

 journal. This will ' enable us to largely extend 

 their scope, and to deal more fully with many 

 matters but lightly touched upon hitherto. We 

 shall welcome gladly any suggestions from readers 

 who may require any point further elucidated or 

 explained. 



It may be helpful if we give a brief list of the 

 most useful books dealing with the microscope, and 

 with the animal and plant life for which the 

 microscope is so essential a means of study, to 

 which also we have appended short explanatory 

 notes. This list appears only as a rough draft, 

 and we trust to have the assistance of our readers 

 in making it more complete or in amending it in 

 any way. 



In conclusion, may we earnestly urge upon our 

 readers the necessity of taking up some particular 

 subject of study, and of using the microscope as 

 a means to that end, rather than as an interesting- 

 optical toy for idly examining heterogeneous 

 slides, which by themselves will soon lose their 

 novelty and interest ? Rightly used, the micro- 

 scope is a means to an end, rather than an end in 

 itself, and is capable of opening out to its owner 

 ever-widening fields of fascinating and absorbing- 

 study and occupation. We cannot all be great 

 scientific discoverers, but we may all be builders 

 of the temple of science, if it be only to lay one 

 single brick in that rapidly growing structure, or 

 to supply a little of the clay or straw out of which 

 such a brick may be constructed by others. 



BIBLIOGRAPHY OF THE MICROSCOPE 



AND MICROSCOPY. 



Technology. 



Batjsch, E. : Manipulation of the Microscope. 

 111., post 8vo. BauscTi $• Lotnb Co. (For 

 beginners.) 1$. 



Beale, Dr. L. S. : How to Work with the Micro- 

 scope. 600 ills., cr. 8vo. Harrison, 1886. 

 (Rather out of date.) 21s. 



Bouspield, Dr. E. C. : Guide to the Science of 

 Photomicrography. 111., cr. 8vo. CJiurcMll, 

 1892, (A thoroughly practical book.) (is. 



Clark, C. H. : Practical Methods in Microscopv. 

 $1.60. 



Cross, M. I., and Cole, M. J. : Modern Micro- 

 scopy. 111., demy 8vo. Bailliere, 1895. (An 

 excellent book. Deals with the use of the 

 microscope and mounting.) 3s. (id. 



Davies, T. : Preparation and Mounting of Micro- 

 scopic Objects, 111.. 12mo. (ribbings, 1896. 

 (Fair.) 2s. (id. 



FREY, Prof. H. : Technology of the Microscope. 

 (Trans.) 111., cr. 8vo. Nnv Tori: 1880. 86.0. 



Frtellander, Prof. C. : Microscopical Techno- 

 logy. (Trans.). 111., llimo. Xe/v Tori'. 1886. 



$i- 



GAGE, S. H. : The Microscope. 165 ills. (New 

 York. An Introduction to Microscopic 

 Methods.) #1.50. 



James, F. L. : Elementary Microscopical Techno- 

 logy. (A Manual for Students.) #0.75. 



LEE, A. B. : The Microtomist's Vade-mecum. 

 Demy 8vo. Churchill. VMM), (.standard work 

 on advanced histological methods.) 15s. 



