Mar., 1904.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



47 



dimensional perception would to our perception seem like 

 two cubes occupying the same space at the same time. 

 They would really represent two separated rubes, but 

 sejjarated in a direction neither up nor down, nor side- 

 ways, nor cross-ways — in a direction of which we, with 

 our three-dimensional conceptions, have no coj^nizance, just 

 as the I'latlander had no cognizance of the meaning of a 

 square being " behind " another square. The ()erspecti\e 

 view of the cube when not seen full face would show tlie 

 Flatlander the two squares only partially occupying the 

 same space at the same time. In like manner we may 

 put it that the super-cube, if presented to us broadside, 

 would look like two cubes occupying the same space 

 at the same time, while in other positions the two cubes 

 would only partially occupy the same part of space. 



Now of this we can get some sort of representation by 

 an interesting experiment with the stereoscope. Just as 

 two flat drawings will give a representation of solidity 

 when appropriately drawn and placed in that instrument, 

 so two solids viewed through it will give some sort of idea 

 of the super-solid. 



The experiment is striking and remarkable. Place in 

 the centre of the field on each side in a stereoscope a 

 solid cube. On looking through the instrument the two 

 combine, and one cube is apparently seen. Now while 

 looking at this one cube move slightly either of the culies 

 as it lies in the stereoscope, and it w-ill be seen that our 

 apparent one cube was composed of two occupying the 

 same space at the same time. With the movement of 

 one cube it is seen to pass partly out of the other, and we 

 have an impression as to our super-solid exactly the 

 counterpart of the Flatlander's impression of the cube as 

 shown to him in the perspective drawing, first full face 

 (the two squares occupying the same space and appearing 

 as one) and then a more side view in which the two 

 squares only partially occupy the same space. 



Using a cube on one side in the stereoscope and a ball 

 of approximately the same size on the other the effect is 

 still better seen, and without moving either the strange 

 spectacle is revealed of a sphere and a cube occupying 

 together the same part of space. 



The experiment affords, of course, but a suggestion of 

 the fourth dimension, yet taken for what it is worth that 

 suggestion is pregnant and of no small interest. 



Conducted by F. Shillington Scales, f.r.m.s. 



Microscopical Materia.1. 



By the kindnoss of Mr. \V. S. Rogers, of I'pper W'arling- 

 ham, I was able la.st month to offer to the microscopical readers 

 of " Knowledgk anij Scikntific Nkws" some "Comfrey" 

 leaves (Symphytum ojjkuiale), which show well the beautiful 

 basesof the leaf hairs. Mr. Rogers states that the appearance 

 referred to is not seen in the leaves when fresh or when dried 

 underpressure, but would seem to be brought into prominence 

 by the blackening of the leaves when they lie fermenting on 

 the ground in autumn. He adds that the material is intract- 

 able to handle, the dried leaf being brittle and inclined to curl, 

 and he has therefore punched them into '^ inch circles. They 

 should, of course, be mounted as opaque objects. I regret 

 that by a printer's oversight this notice was omitted last 

 month, whilst the coupon was omitted the month before, thus 

 causing unnecessary trouble to my many correspondents. 



Preserving Specimens of Orthoptera. 



A recent number ol tlir American J fin mil c/ .IpplicJ 

 Mtcioscopy contains some interesting suggestions for preserving 

 specimens of Orthoptera. .'\s the writer says, (heir compara- 

 tively large size, juicy bodies, when alive or just killr-d, lirittle- 

 ness of limbs and antenii.e wlien dried, llieir pronencss to 

 fading after death, and their liability lo the attacks of mould 

 and nuisciun pests, all seem to conspire against their preser- 

 v.itiou. The larger and more showy specimens are best 

 known, and the smaller and less brightly coloured forms are 

 either entirely unknown or ha\e come to the notice of the 

 \ cry few specialists who have ventured into an .almost forsaken 

 field. There is, therefore, a rich field for investigation for 

 any microscopist who is in want of a fitting direction for his 

 studies. 



Placing these insects in alcohol and other li(|iiid preserva- 

 tives has, in fact, overcome the objection to the soft juicy 

 bodies that so (juickly shrivel and liecome discoloured wlien 

 treated by the ordinary means of pre.serving insects ; but il 

 has the disadvantage of ijuickly effacing the many bright 

 colours conunon to such large niuubers of them, and even 

 changes miiuite structural characteristics, ,so as to render the 

 insects difficult of recognition. It al.so adds greatly to the 

 space taken up l)y the collection, and renders their trans- 

 portation difficult. Still it is an effective preservative 

 against insect pests, such as Dcnncstcs, Sec. Orthoptera can, 

 however, be handled "taxidermically " — ('.f., stulTed much as 

 birds, &c., are stuffed. Instead of throwing the insects into 

 spirits, they should, when captured, be killed in the cyanide 

 bottle. The specimen being then hold in the fingers and 

 thumb of the left hand, with a fine, sharp-pointed pair of 

 scissors open the .abdomen by cutting across the middle of 

 the two basal segments on the lower side, then reverse and 

 cut the opening a trifle larger by nearly severing the third 

 segment. Then extract all the insides (intestines, crop, 

 ovaries, &c.). along with the juices, using fine forceps for this 

 purpose, and wipe out the inside with a small wad of cotton. 

 This being done, the insect may be pinned into a box or 

 wr.ipped in paper and packed away for future use. 



The "stuffing "is carried out as follows. Cut some raw 

 cotton into short pieces, and fill up the insect through the 

 opening made as above, using similar fine forceps and taking 

 care not to stretch or distend the ,al)domen beyond its original 

 dimensions. When the filling is completed draw the edges 

 of the severed segments carefully together, and press the sides 

 of the abdomen into sh.ape with the fingers. This can all be 

 done, after a little pr.actice, in four or five minutes' time. It 

 will be found that the insect will not decay or turn dark, the 

 original colours will be almost entirely preserved, and there 

 is but little danger of attack by museum pests, on of the mould 

 which so frequently spoils objects which .ire long in drying. 



Mouldy specimens can often be saved by being pl.iced in a 

 tin box between wet cloths or blotting p.ipers well sprinkled 

 with dilute carbolic ,icid, and left for twenty-four hours to 

 thirty-six hours, or until sufficiently soft not to break when 

 h.indled. Then pour some alcohol into a dish, and .add to it 

 about one-twenfieth as much liquid carbolic acid. With a 

 camel-hair brush carefully clean the entir(^ insect, taking care 

 to wash every portion with the niixttue of alcohol and acid. 



In arranging in the cabinet the suggestion is made that 

 nuich sp.ace can be economised by directing long antennas 

 backwards along the sides of the insect, and by folding and 

 crossing the legs beneath the body. In the Saltatoria. or 

 jumping forms, the pin should be inserted near the back edge 

 of the pronotum, a little to one side of the middle, .and direct- 

 ing it to the rear, letting it pass downward through the meso- 

 thorax, tliereliy tightly fastening together the two sections of 

 the body. In the other forms, Bliillnidfd, Mmtlniiltn. and 

 Plmsiiinuic-ii, the pin should be inserted l)ehind the pronotiuu 

 through th(t middle of the body, taking care to select a solid 

 portion for this purpose, without running the pin through the 

 basal portion of any of the legs. 



The "Argus" Attachable Mechanical 



Stage. 



This stage was designed for use with the "Argus" micro- 

 scope, noticed in the January issue of " Knowlkdgh," p.age 21, 

 but it can be fitted to any ordinary microscope, being attached 



