Sept., 1904] 



KNOWLEDGE >.\; SCIENTIEIC NEWS. 



225 



Microscopica.1 Table. 



A correspondent, writing over the initals J. Q. T. 

 writes from Queensland Australia : — "At various times 

 I have seen in your columns descriptions of work-tables 

 for microscopy, and I venture, therefore, to send a 

 description of how I made my own. The top of my 

 table is made of half-inch pine, 36 inches by 16 inches, 

 and is raised on four legs 30 inches from the ground. 

 To make the table steady, I screwed on cross-pieces at 

 both back and front, and at the sides, as illustrated. 

 The lower front and back cross-pieces were 2 2i inches 

 from the upper cross-pieces, and upon these 1 screwed 

 two narrow boxes 22 J inches in height, 16 inches deep, 

 and 9 inches wide. To the front of these I .ittachcd 

 doors by means of i-inch hinges, and arranged a 

 simple wire hook to fasten them, though a small lock 

 or bolt would doubtless be preferable. The cupboards 

 thus constructed contain as much as possible of my 

 apparatus, excluding, of course, stock-bottles of re- 

 agents, etc., and are fitted with shelves in the follow- 

 ing way. In the left-hand cupboard there is only one 

 shelf for my objective jar (in this climate it is only safe 

 to keep object-glasses in an air-tight j;ir with calcium 



turn-table, brushes, htittles of cement and varnish, etc., 

 and so on. If work has to be left suddenly, a bell-jar 

 is placed (jver the niii-ros(-ope to protect it from dust. 

 To the front right-hand corner of the table is screwe<l a 

 piece of i inch pine, 2 inches wide and S inches deep, 

 so that 4 inches are on the t.-ililc and 4 inches pro- 

 ject ; to this is clamped a small microtome. Wlicn 

 using the table as a support for a photo-micrograpliic 

 camera it was found to vibrate unpleasantly, and this 

 I obviated by the following simple device. Eight 

 pieces of 2-inch wooti, each 4 inches square, were 

 taken, and in four of these holes were drilled to take 

 the feet of the table-legs, and they were then screwed 

 to the top of the other four pieces of wood with pieces 

 of rul)l)er between (1 made use of some old rubber tyre- 

 tubes). All tile bottles except those containing mount- 

 ing media are lilted with corks and rubber-capped 

 pipettes. I'o !.;i\i' the table a finished appearanci' I 

 stained it with the following mixture, which was re- 

 commended some years ago in the -American ' Journal 

 of .Applied Microscopy ' : (a) Copper sulphate, 25 parts ; 

 potassium chlorate, 25 parts ; water, 200 parts. Dis- 

 solve the salts in hot water, apply hot, and give a 

 second coat when the lirst is dry. Then apply (/') 

 aniline oil, 12 parts; hydroc-hloric acid, icS parts; 

 water, 100 [Kirls. This second solution must be ap- 

 plied cold. The power of the stain is much increased by 

 subsequent washing with hot soap-suds and water. 

 This stain gave a line black, which is not affected even 

 by nitric or sulphuric acid if they are C|uickly wiped 

 off. My water supply consists of a large bottle (con- 

 taining about 80 ozs.) placed on a shelf to the right of 

 and above my table. From this comes a siphon of 

 glass tube with rubber joints (rubber being perishable) 

 ending in a fine jet a few inches above the table rmd 

 closed by a clamp. The sink is a large enamelled 

 bucket to receive waste liquids, and there is a tin box 

 for waste paper, broken glass, etc." 



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Notes and Queries. 



f^caatrjT jioQrd. \ 



chloride), immersion oil, and purely optical accessories. 

 In the space beneath I place the microscope itself in its 

 case. In the right-hand cupboard the shelves are much 

 more numerous, and are fitted so as to run in grooves. 

 The upper shelf contains the reagents. For this I took 

 a thick 2-inch board, pierced it with holes from one 

 inch to three inches diameter, and then screwed it on 

 top of a i-inch board as shown in the sketch. .'\t 

 one end T gouged out a groove 8 inches long, 3 

 inches wide, and i inch deep to serve as a useful 

 receptacle for section-lifters, brushes, etc., which 

 should be conveniently at hand. It should be noted 

 that the 2 inch holes in this shelf are the proper size 

 to hold Grubler's 100 cc. reagent bottles, which I have 

 found very useful. The bottles containing fixing, 

 staining, clearing, etc., fluids are placed each in its 

 proper hole, and on starting work the board is brought 

 out and placed on the table. The shelf below is 

 utilised to carry slips, cover-glasses, troughs for pond- 

 life, etc. In the next shelf are kept note-books, pens 

 and pencils, ink, paper, camera lucida, and other 

 accessories for recording observations ; below this a 



Reversal of Image in Using Beale's Camera Lucida. 



A correspondent writes : " In m.'tkinf; drawings of sections, 

 when it is desired to sketch in the outlines by using the camera 

 lucida and to put in the details freehand with direct vision, 

 Beale's reflector, with its jiartial reversal of the image is 

 notoriously awkward to work with, but its principal fault may 

 be counteracted by the following procedure, so far as work 

 with the lower powers is concerned. Put the slide upon the 

 stage upside down, i.e., with the cover-glass underneath, and 

 focus through the thick glas.s slip, sketch the rough outlines, 

 &c., of the section, then remove the reflector, reverse the slide 

 so as to focus through the cover-glass as usual, and with a 

 higher power if necessary, fill in the finer details frc^ehand, 

 using direct vision. Kach part of the section will thus be 

 found in its proper place in th(^ outline sketch. Care must 

 betaken not to knock the cover-glass sideways when removing 

 it. If the stage aperture is small, the slip can be supported 

 at the ends by pieces of glass." Another correspondent, Mr. 

 C. H. Caffyii, suggests drawing on a sheet of paper placed on 

 a piece of carbon or black-leaded paper, by which means the 

 outlines will be found reversed when the paper is turned over, 

 and can then be filled in without the use of the camera 

 lucida. 



{Communications and enquiries on Microscopical matters are invited, 

 ^ and should be addressed _[to /•'. Shillington Scales, '^Jersey," St. 

 IJarnal'iis h'mid, Cainlirnt^'e ] 



