356 PROCEEDINGS OF THE 



index is 147 ; it forms a suitable mountant for many algae, 

 insects and Crustacea, and is of special value when it is desired to 

 retain the natural colour. Carbonate of lime is soluble in glycerin, 

 so that it must not be used for calcareous objects. Glycerin is a 

 difficult substance to seal. Prof. Birge, an American authority 

 on Entomostraca, recommends their being mounted in glycerin 

 and sealed by paraffin wax of low melting-point. Mr. Curwen 

 found paraffin wax unsuitable, as it contracts when solidifying 

 and does not adhere well to glass. After trying about forty 

 different wax compounds, he adopted a material known as soft 

 red wax. The composition appears to be beeswax with a small 

 proportion of Venice turpentine and a red dye ; it is used as 

 a temporary adhesive for experimental puposes, and may 

 be obtained in sticks from dealers in chemicals and scientific 

 apparatus. Mr. Curwen then described the method of mount- 

 ing. Entomostraca, or water insects, are killed by heating 

 the water until motion ceases. They are then transferred to 

 a 25 per cent, solution of glycerin in distilled water ; pipettes, 

 needles, brushes, bristles and small feathers being used for 

 different classes of objects. The pin feathers of a woodcock 

 mounted in a handle are very useful for large Entomostraca, etc. 

 After at least twenty-four hours in the 25 per cent, solution most 

 of the smaller Entromostraca can be mounted in pure glycerin, 

 but the large forms, also algae and most insects, require 24 hours 

 in 50 per cent, and 24 hours in 75 per cent, before mounting in pure 

 glycerin. The mounting may be done in 50 per cent., 75 per cent., 

 or 100 per cent, glycerin, but 100 per cent, should be used where 

 possible, as it is easier to manipulate. The following items are 

 required for mounting : — (1) Filtered glycerin that has been 

 allowed to stand to eliminate air bubbles, in a bottle having a glass 

 dropping rod passing through a rubber cork. (2) Slips and 3/4 in. 

 covers. The slips should be thin to avoid overheating the objects 

 when sealing. (3) Wax discs about 1/16 in. thick cut from the 

 stick and then cut in halves, the amount of wax in a semi-disc being 

 about enough for an average seal. Thin slices melt easily before 

 the object is unduly heated. (4) An assortment of squares of 

 card or celluloid of various thicknesses about 1/32 in. square. 

 (5) A spirit lamp with a small pointed flame. (6) Forceps, needles, 

 and other dissecting tools and a dissecting microscope. The 

 procedure was then described, specimen slides being made on the 



