PREPARATION AND MOUNTING 73 



has to be done with these objects is to first soak 

 them in turpentine, and then proceed to mount. 



The mounting is accomplished thus : First clean 

 a glass shp and a suitable cover-glass. Lay the 

 slip on the mounting-table, which must be heated 

 with the spirit lamp. The slip will be warm enough 

 when the heat is no more intense than can be borne 

 when the finger rests upon it. Then a couple of 

 drops, more or less, of balsam are dropped from the 

 point of the glass rod exactly in the centre of the 

 shp. The object is taken out of the turpentine 

 by means of a needle, the forceps, or a proper 

 section Hfter (costing about 6d. at the dealer's), 

 placed in the balsam, and worked well into it. 

 Now we make an examination with a pocket lens 

 to make sure that the object is properly in the 

 centre, and that no air-bubbles cling to it. All 

 being satisfactory, we pick up the cover-glass with 

 the forceps, warm it in the spirit flame, and lower 

 it on to the balsam, and apply gentle, even pressure. 

 It is often advisable at this stage to apply a spring 

 chp to the mount, and to allow it to remain in the 

 chp for some hours. Suitable clips cost about 

 Is. 6d. a dozen. Sufficient balsam must be used to 

 fiU the entire space under the cover. Any overplus 

 can be cleaned off with methylated spirit after the 

 balsam has set. Balsam mounts do not need 

 ringing with enamel, although the worker may rmg 

 them if he likes and thinks the appearance is im- 

 proved by so doing ; and it will be noted that 

 ordinary balsam mounts do not require cells. Air- 

 bubbles sometimes present . difficulties ; if they are 

 not involved in the object they are a negligible 



10 



