814 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the pasteboard. It is then placed under the Microscope, and moving it 

 so that the edge of the pasteboard is just visible, pass up one side and 

 down the other, and every particle of the sand is brought into view 

 without loss of time in searching over the same portions many times, 

 and perhaps entirely omitting other. It is surprising what a quantity 

 of sand can thus be looked over in a short time by this systematised 

 labour. 



The shells may be picked up by a very fine needle dipped in 

 turpentine, or a very small camel's hair brush. 



Not being satisfied with the ordinary slides and cells for this class 

 of objects, the author has devised a slide which he thinks serves the 

 purpose admirably ; it is made as follows : — The slide itself is of 

 wood, of the ordinary size, and about 1/10 in. thick. Through its 

 centre is bored a hole 1/2 in. in diameter. Over the back of this is 

 pasted a strip of stout paper. The hole in the slide with the paper 

 back constitutes the cell. In the bottom of the cell is pasted a disk 

 of coloured paper, cut with a gun- wad punch, to serve as a background 

 for the " mount." To give a neat finish, a brass curtain-ring which 

 just fits in the hole is fastened in with a bit of cement. The edges of 

 the slide are now bound or covered with coloured tissue paper. The 

 shell may now be arranged in the cell, and the cover-glass dropped in 

 upon the brass ring, the top of which has been covered with cement. 

 A suitable label the whole size of the slide is now pasted on the 

 front, and a plain one may be put on the back. 



Should a shell be very rare, and it is desirable to show both sides, 

 a piece of thin glass may be let into the back of the slide, and 

 the curtain-ring placed upon this instead of the paper background. 

 Such a slide would need a hole in the back as well as in the front 

 label. 



When these slides are finished with pretty and suitable labels 

 they make a fine appearance, pack and carry as easily as so many 

 slips of wood, and if made of white bass wood do not warp. The 

 porosity of the wood prevents any accumulation of moisture upon the 

 cover-glass. 



Hsematoxylin as a Reagent for Non-lignified and Non-suberized 

 Cellulose Membranes.* — The reagent described by E. Giltay in this 

 paper and which he finds to be very sensitive and preferable in most 

 cases to those hitherto employed for the purpose, is prepared as 

 follows : — 



To 5 CO. of a solution of hsematoxylin (7 grams of hsematoxylin 

 to 50 cc. of water) add 100 cc. of a solution of alum (3/4 per 

 cent.). The mixture should be prepared two days before it is re- 

 quired, and as it speedily becomes turbid, a small amount is filtered 

 each time before use. The sections to be stained are left in from 

 5 to 15 minutes, according to circumstances, and subsequently 

 mounted in glycerine, oil of cloves, or Canada balsam. In the last, 

 or in oil of cloves, the colours keep for a long time. 



In general this reagent and that of Schultze have the same action 



* Arch. Neerland. Sci. Exact, et Nat., xviii. (1883) pp. 437-52. 



