534 SUMMARY OF CURRENT RESEARCHES RELATING TO 



1. By taking a strip of pine wood, half an inch thick and of 

 suitable length and breadth, and giving it a suitable shape, making a 

 hole in the larger end of such size, that when lined with a bit of cloth, 

 it fits tightly on and over the nose of an inch objective. In the smaller 

 end another hole is to be made, into which a slightly tapering cork is 

 pressed from above, in order to carry the forceps. Having fastened a 

 bristle into the jaw of the stage-forceps by means of a drop of glue, 

 and made a small hole for a guide, the shank of the forceps is forced 

 into the cork and fastened in position with sealing-wax, and the 

 finger is complete, with no expense but an hour's labour. 



2. With still less labour, the nose-piece can be substituted for the 

 above wooden carrier, screwing the cork into the nose-piece instead 

 of the extra objective, and attaching the forceps as before. 



In either case, the elasticity of the cork holds it in place with 

 sufficient firmness to admit of its being rotated with finger and thumb, 

 so as to move the point of the forceps with the bristle to the right or 

 left as may be desired. The lifting of the object is done by means of 

 the joint in the forceps. 



Although these fingers may not be as perfect as those of more costly 

 construction, yet combining as they do all movements essential to any 

 finger, they may, the author considers, be used in an emergency, and 

 in skilful hands will be found capable of effective work. 



Mounting with Glycerin-jelly.* — Grlycerin-jelly has long been 

 known as a mounting medium, but most persons have found some 

 difficulty in its use. The precipitation of balsam by all watery 

 objects, especially aquatic insects and fresh-water algee, induced Mr. 

 W. H. Seaman to devise the following method of manipulation, by 

 which glycerin-jelly may be used with great rapidity, avoiding the 

 tedious preliminary preparation necessary for balsam : — 



The jelly is made by dissolving transparent isinglass in sufficient 

 water, so that it makes a stiff" jelly when at the ordinary working tem- 

 perature of the room where the slides are mounted, add one-tenth as 

 much good glycerin and a little solution of borax, carbolic acid, or 

 camphor-water. The mixture should be well filtered while hot 

 through washed muslin or other fabric, as it will not run through the 

 usual filter-paper, and the subsequent addition of a little alcohol 

 improves its working. Objects, if perfectly clean, may be transferred 

 at once from water to this medium, which should be slightly warmed 

 before using, if not perfectly fluid. The cover is adjusted and the 

 slide put away until a number have accumulated. The cover should 

 not be pressed down too hard, and a liberal amount of jelly used to 

 allow for shrinkage in drying. The slides may be finished as soon as 

 the jelly has set, or they may be left for several days. If air bubbles 

 are entangled they will usually escape while drying, or they may be 

 driven out by warming the slide a little. When ready to finish the 

 slides, take them to a water cooler and let the ice-cold water drip 

 over them, while with a camel's-hair brush, rather stiff, all the super- 

 fluous jelly may be readily brushed away by the aid of the flowing 



* Amer. Mon. Micr. Jouru., ii. (1881) pp. 4-5. 



