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HARDWICKE'S SCIENCE-GOSSIP. 



make them known through your journal, Mr. Editor, 

 because I know it is seen by all microscopists on 

 this side of the ocean, as I feel must likewise be the 

 case in England. Unfortunately, we have no medium 

 published in this country, as yet, through which 

 microscopists can communicate one with the other; 

 so we have to depend on you and collaborateurs, 

 the Quarterly, the Monthly, and the Journal of the 

 Quekett Club ; all of which we welcome with open 

 arms. 



My first dodge, then, is a form of drop-bottle to 

 hold test-solutions, as acids, staining material, and 

 the like, which are so commonly used in small quan- 

 tities applied directly to the object whilst under 

 examination upon the stage of the microscope. 

 Bottles with nicely-ground and tapering stoppers 

 can be procured, we are informed, in London, but 

 not readily in New York, or even if they can, they 

 cost considerable, an item worthy of very serious 

 consideration by beginners ; besides, they do not 

 answer for all purposes, for only a drop of a certain 

 and small size can be taken up at one time. It is 

 true that there are those little bottles having caout- 

 chouc-covered funnels fitted into their necks, but I 

 never found them very useful ; and they, too, cost 

 money, less or greater, depending upon the con- 

 science of the dealer. With all of these, if a large 

 quantity of the fluid is required, it must be fished 

 out in successive drops. Now my contrivance, or 

 dodge, does away with all of these objections; with 

 it a small drop or a large quantity, as desired at the 

 time, can be taken up ; and above all, the greatest 

 recommendation is that the apparatus can be got 

 up by any one in a few minutes, and costs very little. 



The first form it assumed was a small narrow- 

 necked phial, having a perforated cork, through 

 which a glass tube was passed, and this glass 

 tube was drawn out to a fine orifice at its 

 lowest extremity. By means of such a dip-tube, 

 of course, any amount of the contained liquid 

 can be extracted, shifting the tube up or down 

 through the cork as occasion required. But alter 

 several such bottles had been in use for some time, 

 there was found to be one very great objection to 

 it in this form. That is to say, many of the liquids, 

 the alkaline solution for instance, acted upon the 

 cork, and in time it also shrunk, and dried so that 

 the liquid evaporated. Of course, a little will also 

 evaporate through the tube itself, but this amounts 

 to very little, except in the case of alcohol, ether, 

 or the like. So that I have modified my dropping- 

 bottles, and use a short piece of caoutchouc tubing 

 about half an inch long, placed around the glass 

 tube, and in lieu of the cork. This fits perfectly 

 tight, is unacted upon by most reagents, and, at the 

 same time, is somewhat elastic, so that the tube is 

 not easily broken by an accidental blow, if it, happen 

 to be struck sharply when reaching across the table. 

 Then, again, the upper end of the tube may be 



stopped with a cork to prevent evaporation, or, 

 what is still better, the caoutchouc tube attachment 

 may be applied at top, as described in Science- 

 Gossip, vol. iv. p. 2G0. But 1 think our curator, 

 Mr. Jackson, who is well known amongst us as a 

 great contriver of dodges, has suggested an improve- 

 ment on this rubber tube at the top of the pipette. 



In our apothecaries' shops, and I suppose in 

 yours also, are to be found so-called "nursing- 

 bottles," which have attached to the end of their 

 exit-tubes caps or " nipples " made of caoutchouc. 

 One of these may be slipped over the end of the 

 pipette, and tiie little hole in its rounded extremity 

 stopped with a drop of sealing-wax. When this is 

 compressed, the air is driven out of the tube ; and 

 when the pressure is removed, the fluid enters and 

 is retained as long as we like, to be driven out by 

 pressing the rubber bulb again. 



My next dodge is a movable table or stand to 

 hold both the microscope and lamp, so that they 

 can, together, be passed about from one person to 

 another sitting at the same table. This also can be 

 made at home, and costs very little. It consists of 

 a stout piece of board made of such wood as is 

 heavy, and which does not readily crack or change 

 shape by shrinking or warping. Black walnut I 

 find to answer xevy well, and to be sightly at the 

 same time. But it should be oiled so as to prevent 

 its absorbing moisture. It is cut into a triangular 

 form, and has the corners rounded off. The size is 

 such that the lamp will stand in one corner, whilst 

 the microscope occupies the position midway 

 between the two other corners, and' is at a conve- 

 nient distance from the lamp. In the under side of 

 the board and near the corners are screwed three 

 small china drawer-knobs, and upon these the stand 

 rests and moves. These smooth polished knobs are 

 much better and steadier than castors; and besides, 

 with them the stand can be moved in any direction, 

 as they freely slide over a table-cloth or varnished- 

 cloth covered table, and do not mark the surface any 

 more than castors. I am aware that something of 

 the same kind as this has been proposed before, 

 but not so simple in construction, and which could 

 not be so readily made at home, and cheaply. 



Dodge number three is of another kind, and just 

 as practical as numbers one and two. As micro- 

 scopists are so numerous, many of them must 

 possess instruments having such thick stages that 

 although they may be occasionally tempted to try 

 their objectives with extremely oblique light on 

 some "rhomboides" or " pellucida," yet they are 

 unable to do so. And here excuse me if I remark 

 that this seems to be an almost universal fault in 

 the English stands. With us, on the contrary, the 

 fact that any stand may fall info the hands of a 

 resolver of fine-lined test-objects is so generally 

 understood by our makers, that they make the 

 stands of both their low-priced and large instru- 



