42 THE AMERICAN MONTHLY [Feb 



sam and free from specks of dirt. Now put it away on 

 the slip, in a place free from dust, for from two to twelve 

 hours. Delicate specimens will not stand exposure like 

 the more hardy ones. In the case of rock sections, this 

 process may be extended to 18 or 20 hours. After expo- 

 sure take the cover glass in the forceps, place a very small 

 portion of the balsam and benzole in the centre of the slip, 

 place the cover glass in position, gently warm it over a 

 spirit lamp with the flame turned down low. Press down 

 keeping the specimen in the centre as nearly as possible. 

 When cold, clean off any excess of the media. This is 

 done with methylated spirit. Having cleaned all ofl", run 

 a ring of cement round and when this is dry, finish to 

 taste. 



Other objects may be mounted in balsam, Polycistina, 

 Foraminifera, etc. Pure balsam is the best for these. Take 

 an ordinary retort stand and on one of the rings, place a 

 piece of metal, iron or brass, about 1-16 in. thick, Sin. or 

 4 in. wide, and 4 1-2 in. long. This will hold four slips at 

 once. It is best to fasten metal to the ring in some way. 

 A small piece of solder will do. This is only to prevent 

 its being upset, slides and all. Take a piece of tin and 

 bend it into the shape of a shallow box without a lid, 

 about 1-2 in. or 3-8 in. deep. If this is made about 1-8 or 

 1-4 in. smaller allround than the metal plate, it willform a 

 sort of miniature oven when placed on the plate. It is 

 principally to keep off dust, but it must be used, if good 

 results are desired. Have your objects all ready, quite 

 dry and clean. Take your 3 X 1 in. slip, place a drop of 

 balsam in the centre, about 3-8 in. in diameter or less. 

 Next take some up on the point of a scalpel, or in a small 

 piece of paper. Shoot them into the centre of the balsam, 

 gently stir with a needle point to make them sink, place 

 your slide on the metal plate you have prepared, adjust 

 to proper height over your lamp and turn the flame down 

 very low so as to get gentle heat. Very little heat is re- 



