MOUNTING INSECTS. 309 



A clip should be used during the last operations, but only to prevent 

 displacement of the cover. The slide must now be put aside in a 

 warm place, until the balsam is hard enough to allow the super- 

 fluous portion to be removed safely. Sufficient balsam should be 

 left to form a sloping edge around the cover- glass, and it should be 

 hardened for a few days after cleaning. Be sure that the balsam is 

 quite hard before applying brown cement. The ease with which an 

 object can be rearranged, or a chance air-bubble removed, without 

 disturbing the cover-glass, constitutes the chief advantage of using 

 beads. A supply of different sizes should be kept, and the size used 

 must be regulated by the thickness of the object. Pure balsam in 

 collapsible t Jbes is to be strongly recommended, on account of the 

 nicety with which the quantity of balsam required for mounting a 

 slide can be regulated. The neck of the tube should be wiped with 

 a clean cloth moistened with benzole before the screw-cap is re- 

 placed, in order to prevent the possibility of a little balsam harden- 

 ing in the screw, and so prevent the easy removal of the cap when 

 next required. (Scientific and Literary Gossip.) 



Preparing and Mounting Dissections of the Appendages, etc. A. C. 

 Cole's method in dealing with the parts of spiders will also apply to 

 insects. The spinnerets, legs, and falces having been respectively 

 removed are placed separately in liq. pot. for 24^36 hours ; then 

 soaked in water to remove the potass ; then placed in acetic acid (in 

 which such parts of insects, etc., may always be preserved until re- 

 quired for mounting); then again soaked in water ; then placed in 

 strong alcohol for a short time ; then cleared by means of oil of 

 cloves, and, lastly, transferred to turpentine, and mounted without 

 pressure in cells (Studies in Microscopical Science, in. sect, iv.) 



Mounting Minute Insects and Acari in Balsam. Mr. A. D. Michael 

 describes his process as follows : He first kills the creatures in hot 

 water or spirit. Hard insects and Acari are best killed in hot water, 

 which causes them to expand their legs, but water rather injures 

 minute flies, and spirit is better for them. Next wash the objects 

 thoroughly in spirit and clean with a badger's hair, clean me- 

 chanically and by washing in spirit. Place the object on a glass 

 slip and arrange it with the hair, leave it in spirit for such a time 

 as experience suggests, tilt the slip so as to drain off the spirit, but 

 not to dry the object, which should never be allowed to dry from the 

 first process to the final mounting. Having drained off the spirit, 

 drop on the object a little oil of cloves, which is better than turpen- 

 tine ; slightly warm the slide and put on a thin cover-glass, which 

 must be supported so as not to touch the object ; leave it until 

 thoroughly soaked. If necessary, remove to a clean slip for the 

 final mount. It may be necessary to arrange the object more than 



