8 



MANIPULATION. 



In order to obtain a comprehensive view, the organs 

 must be extruded, and made transparent, this is very 

 simple. Having removed the body near the thorax, it is 

 soaked in a 10 per cent, solution of Caustic potash, for 

 about 24 hours to 2 or 3 days, according to the size and 

 nature of the body. Or it may be boiled in a test tube, 

 for a short time in the same solution, which is a quicker 

 method. When it is quite soft, it is taken out and 

 placed in a shallow dish of water. The body is then 

 gently tapped with a small bent spatula or a brush, 

 when the parts will fly out. If a little pressure be now 

 put on the junction of the harpes, they will separate, 

 exposing the interior with all the parts beautifully 

 displayed. The Alkali must then be carefully washed 

 out of the preparation, which should next be slid on to 

 a glass slip, arranged with needles, and covered with a 

 small piece of glass, (I generally use a 3 x 1 inch slip 

 cut into 3, i.e., one inch square), which gives about the 

 right amount of pressure. A small quantity of Absolute 

 Alcohol should now be allowed to flow in to remove the 

 water ; after dehydrating for about half an hour, Oil of 

 cloves must be run in from one side, and allowed to 

 soak in until the parts are clear and free from air 

 bubbles. The object is then ready for mounting. This 

 can be easily done by placing a couple of drops of 

 Canada balsam in benzole, slightly spread on a clean 

 slip to fit the cover glass. The preparation should now 

 be gently lowered into the Balsam, right way up ; the 

 cover glass placed over, and the slide put aside to dry. 



I find it better not to hurry the drying, and 

 patience pays well at this stage. 



Should the mount be very thick, a cavity slip 

 should be used. I do not recommend the use of clips, 

 though in very tough species, they are useful if carefully 

 applied to the edges of the cover glass. 



