ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 579 



white wax. The slip upon which the cell is to he made is placed on 

 the turntable, and while it is spinning, touched with the point of the 

 wax pipette, previously heated so that the wax may flow out readily. 

 A wax ring is thus made quite as easily as one of varnish, and if the 

 ordinary pharmaceutical white wax be employed, it will adhere very 

 tenaciously to the slide. It is obvious that many varieties of rings 

 may be made by modifying the temperature of the wax or even by 

 warming the tlide, and as an operation of this kind generally requires 

 some little practice in order to obtain the best results, a few failures 

 at the outset should not discourage the operator from further 

 attempts." 



Miller's Caoutchouc Cement. — Mr. E. Miller, while not claiming 

 to have discovered any new substance, bas hit upon a new method of 

 combination by which a material is obtained easy and quick to work 

 and reliable in its results, and available both for making and sealing 

 cells. It has stood a test of eighteen months. 



The following are his directions for using it : — 



To turn Cells. — Centre the glass slide on the turntable, and 

 with a camel's-hair brush previously charged with sufficient cement, 

 mark off the foundation of the cell in width and size required, the 

 turntable being somewhat rapidly revolved ; dip more cement and 

 apply directly before the first layer can set, and so on, always 

 touching the top of the stream only, until the cell be raised to the 

 height desired, then lay the slide aside in a level position to dry. 

 Slight cells dry in a few hours, deep cells, say ^ of an inch, in two 

 or three days. One hundred perfect cells may be turned in an hour 

 by a beginner, and nearly twice that number by an adept. (Keep the 

 brush clean and the bottle tightly corked.) 



To mount in Glycerine, Oil, Canada Balsam, or other Fluids. — 

 Take a cell perfectly dry, apply or turn a sufficient layer of the 

 cement round the top of the cell, slightly overfill the cell with 

 glycerine, and put in the prepared object, place on the glass cover 

 (previously tested to fit), press down the centre and edges of the 

 cover until it is firmly in position, and with a damp brush gently 

 remove the expelled glycerine ; test again by slight pressure that the 

 cover is on the cement, and lay aside to set. A few hours afterwards 

 the slide may be immersed in a basin of water and thoroughly 

 cleansed with a camel's-hair brush, wash again if necessary, and when 

 thoroughly freed from all traces of glycerine and quite dry, turn a 

 layer of the cement over the cell embracing the rim of the glass 

 cover, and finish to taste. The slide will then be found to be durably 

 sealed and the fluid permanently confined. 



These directions apply to mounting objects in oil or fluid 

 Canada balsam, except the use of water to clean them ; the supei- 

 fluous oil or balsam must be removed by a brush dipped in benzole, 

 the brush being continually wiped between a cloth. Do not use 

 balsam diluted with ether or chloroform. 



Mounting in Phosphorus. — The following is the note which 

 Dr. Morris has written out, as mentioned, post, p. 591. It must, 



2 q 2 



