for the gum to 
obs cell is the ity depth for the object, the aes should: 
ust press on the latter enough to retain it in positio: 
a When the gum has hardened, and the cover is qui ite nat and | 
re, I take up with a small pipette a little benzine, and apply 
‘one of the openings cut in the card cell, when t the Lang 
nly runs in and fills up the cell, and in a few mm tes the 
lis ~ yaa hoes the benzine, which has not the slightest 
ent. 
nr some balsam, 
Soft enough to drop eudity trom a bit of wire at a tnperatare 
about 60°, “ one of said openings, warm the slide gently. y, and . 
> balsam lls up the cell, and, if any bubbles appear, hey 
‘yl Vanish in a iow hours. 
the balsam will in a day be 
eh is done on the turn-table by “ turning” away 
and leaving a ring ¢ of a 
bit od rag wet 
