28 



THE AMERICAN MONTHLY 



[February, 



ing is here mentioned that is not 

 really useful in general mounting. 



Treating first ot the apparatus, a 

 small alcohol lamp and a brass mount- 

 ing table will be necessary. The lat- 

 ter can be obtained, very neatly made, 

 from dealers in microscopical appa- 

 ratus, but a good substitute.can be de- 

 vised by supporting a plate of brass 

 about j^ of an inch in thickness in 

 any convenient w^ay over the lamp. 

 The brass should be placed so far 

 above the lamp that the heat from the 

 latter will cause Canada balsam to 

 harden rapidly without changing its 

 color. If balsam is heated too much 

 it turns yellow. A temperature just 

 a trifle higher than the hand can bear 

 is about right. 



Needles mounted in wooden han- 

 dles can be purchased, or they may 

 be readily mounted at home. There 

 should be several of them, of difter- 

 ent sizes, very delicate ones to use in 

 working on the stage of the micro- 

 scope, others for ordinary use. One 

 method of mounting a needle is to 

 break off the eye and sharpen the up- 

 per end. Then seizing the needle 

 firmly in a pliers or a vise, force the 

 sharpened end well into the wood, in 

 which process a hammer may be nec- 

 essary. In this way the natural point 

 of the needle is left uninjured. The 

 needle should project about | of an 

 inch from the wood, and the latter 

 should be cut down to the needle, like 

 the sharpened end of a pencil. Two 

 rather strong needles should be in- 

 serted in one handle, close together, 

 as this makes a very useful instru- 

 ment. 



Another method of inserting the 

 needles is to split the end of the hold- 

 er, lay the needle in position in the 

 slit, and secure it in place by wrap- 

 ping thread around the holder, thus 

 closing the slit, after which the whole 

 may be covered with shellac or liquid 

 marine glue. 



A small pair of surgeon's scissors, 

 such as are used in operations on the 

 eye, form an essential part of one's 

 outfit for dissecting small objects. 



Straight scissors are better than those 

 with blades turned at an angle — the 

 crook is always the wrong way for 

 the work now under consideration. 

 A small knife with a keen edge is also 

 necessary. Both these instruments 

 can be obtained, of proper form, from 

 dealers in microscopes or in surgical 

 instruments. 



Forceps are to be very carefully 

 chosen. We would advise three 

 kinds, two small ones of steel, which 

 should be the best of surgeon's fine 

 forceps, one straight, the other with 

 curved ends. The points of these 

 should come accurately together, as 

 they may be required to pick up the 

 smallest particles or filaments. The 

 third pair should be of brass with the 

 ends curved, carefully made, and 

 about 5 inches long. Such forceps 

 are not very often seen, but we selected 

 a pair from Mr. Woolman's stock long 

 ago, and they have proved inv^aluable 

 in many ways. They are useless for 

 dissecting purposes, for which the 

 steel ones are eminently fitted, but 

 they are useful for innumerable other 

 purposes, to which the steel ones are 

 usually applied with great inconve- 

 nience. They will hold a thin cover- 

 glass securely — which the fine steel 

 ones were never known to do. They 

 require so little force to close them 

 that there is no fear of dropping 

 a specimen by tiring the muscles, or 

 injuring it by too much pressure. 

 They are invaluable for dipping into 

 bottles of water to select filaments of 

 alg£e, portions of plants, etc., for ex- 

 amination, or for handling sections 

 and objects of all kinds. 



Glass tubes are almost universally 

 used in microscopical work for dip- 

 ping up water and other fluids, but in 

 many cases solid glass rods are pref- 

 erable, since they can be more readily 

 cleaned. Tubes should be cut of the 

 desired length, and one end drawn 

 off to a smaller aperture, for which 

 purpose a spirit lamp aftbrds sufficient 

 heat. Heat the tube, and gradually 

 draw it out, then draw a file across 

 the narrowed portion and break it 



