552 H. J. QUILTER OX TAKING INTERNAL CASTS OF FORAMINIFERA 



slide heated on a warm stage, and maintained at a temperature 

 sufficiently high to keep the wax in a fluid state. The shells should 

 now be transferred to the wax on this slide, and arranged so that 

 there is a clear space round each. The slide is then allowed to 

 cool ; when the wax is quite hard, a camel's-hair pencil, cut 

 square across so as to make a stiff brush, is dipped in benzole, 

 and the shells are well brushed with this until the wax above and 

 around them has been removed. Care must be taken that the 

 brush does not retain too much benzole, or the casts will be spoiled. 

 They are then well w^ashed with a camel's-hair brush and soap 

 and water ; after this treatment they should be quite clean, and 

 remain attached to the slide by a small pellet of wax. The 

 slip with the shells attached is now put into a beaker, and 

 sufficient water poured in to cover them ; hydrochloric acid is then 

 added until brisk effervescence takes place. The slip is left in 

 this as long as any gas is given off ; it is then taken out, washed 

 in clean water, and left in a cool place to dry; when quite dry 

 it is ready for mounting. 



Sometimes during the treatment with acid and water the shells 

 or casts float off" the slip, and must then, when all the shell has 

 been dissolved, be picked out one at a time, dried, and remounted 

 on the slip with Canada balsam or gum. 



Little trouble will be experienced when taking casts of the 

 larger forms, but with the smaller ones it is different, as these 

 will be found to become detached from the slide towards the end 

 of the treatment with the benzole and brush ; but as a rule, when 

 this happens, the outsides of the shells are clean enough, and they 

 can then be transferred to the acid and water, and afterwards 

 treated as before described. 



Journ. QuefMt MicvoscoplcoA Club, Scr. 2, Vol. Fill., So. 53, November 1903. 



