April 1, 1SGS.] 



HARDWICKE'S SCIENCE-GOSSIP. 



91 



MICROSCOPY. 



Pocket Cabinet. — Mr. W. Moginief of 244, 

 High Holborn, has designed a compact little pocket 

 cabinet, which is made of pine or oak, and contains 

 three or four divided trays opening on pivots like a 

 French rule, so that any object in any tray maybe 

 found at once. Each tray holds six objects, and 

 the whole is very compact for the coat pocket, at a 

 moderate price. 



A Struggle tor Life. — In examining some 

 refuse water from a small aquarium, the contents of 

 which were mostly obtained at the Menai Frith, I 

 found, among a number of interesting, and some, to 

 me, unknown forms, several examples of a large 

 species of Infusorial Animalcule, agreeing in every 

 particular with the Konclylostoma patens of Dujar- 

 din, who includes it in his family " Bursarina." 

 While observing the well-marked characters and 

 elegant motions of this " giant among the pigmies," 

 there dashed wildly into the field, a small Rotifer 



{Colurus), who, appearing unable to stop itself in its 

 rash career, passed at once into the widely-extended 

 mouth of the Kondylostoma, and became enclosed 

 in its transparent body. For a second, the little 

 Rotifer remained quiet ; as if not quite understand- 

 ing what was the matter ; then suddenly beginning 

 to kick violently, it forced its sharp foot through 

 the side of the Animalcule, and grasping with its 

 forceps some vegetable matter, retained between the 

 glasses of the compressorium, it held on stoutly 

 against the whole force of its powerful captor. 

 The affair now became exciting. The Kondy- 

 lostoma struggled to get away ; the Colurus refused 

 to be carried off; and the two antagonists began to 

 revolve rapidly around a centre near the air-bubble 

 figured in the illustration. Slowly the Rotifer was 

 pulled further and further out ; until, at last, its 



widest diameter being free, it escaped. The 

 wounded Kondylostoma swept out of the field ; and 

 the little Colurus, after giving a few final kicks, 

 projected its tufts of cilia and steamed away again, 

 as if nothing very peculiar had occurred. Thus 

 ended one of the countless multitude of strange 

 scenes, revealed only to those who pore down the 

 brazen tubes, and waste the midnight camphine. 

 To the microscopic student what myriads of odd 

 shapes and ways of life become familiar ! Trans- 

 posing the well-worn quotation that the " world is 

 a stage," may he not justly say of this instrument, 

 that its " stage is a world" ? — H. C. R., Kensington. 



Resin versus Balsam.— I have lately been making 

 some experiments with resin for mounting trans- 

 parent microscopic objects in, instead of balsam, 

 and the results are so far entirely satisfactory. I 

 now forward you particulars, as I believe the in- 

 formation may be acceptable to many of your 

 readers. It came to my knowledge that a certain 

 microscopist was in the habit of heating his balsam 

 over a spirit-lamp, for the purpose of driving out 

 the turpentine, and then of softening the result 

 (which is a pure resin) with some fluid, so as to 

 make it workable for mounting purposes. A 

 chemical friend who was present when this in- 

 formation was given me expressed an opinion that 

 benzoin would dissolve the resin, and if pure resin 

 could be obtained all the trouble of driving out 

 the turpentine from balsam might be saved. I 

 obtained a small quantity of pure resin from the 

 works of Messrs. Pechin & Co., of Salford, and with 

 the aid of heat soon obtained the proper mixture 

 for mounting purposes. I have mounted some fifty 

 objects with the mixture, and the results are so far 

 perfectly satisfactory. The air-bubbles soon dis- 

 appear, and the mixture hardens much quicker than 

 Canada balsam. Instead of saturating the objects 

 in turpentine, as I formerly did, I now use benzoin, 

 as I find the latter ferments the tissues much more 

 quickly, and thus drives out those old enemies — 

 so hard to get rid of— air-bubbles. All objects 

 mounted with this mixture should be saturated, if 

 it be but for a moment, in benzoin. Many kinds 

 of animal and vegetable hairs, and various other 

 objects, require only to be dipped into the benzoin, 

 and then mounted directly without further prepara- 

 tion. Other objects require a longer saturation or 

 soaking. Some objects, such as complicated tissues, 

 require several weeks before the whole of the air is 

 driven out. It should be noted that resin is usually 

 more or less mixed up with woody fibre or other 

 matter, so that if any of your readers are inclined 

 to follow up my experiments, they should be careful 

 to select resin for the purpose very carefully, or 

 they may spoil or destroy the very objects they 

 desire to preserve. — Thos. Brittain, 58, Upper Brook- 

 Street, Manchester. 



