492 



FRANK D. ADAMS 



A-T£STP/£CE 

 \ MATERIAL 



_^BRASS PLATE 



/ 2 3 -f 5 



^ ' ' ■ I ■ I . ' ■ ! 

 CENT/ METERS 



plate and a portion of the embedding material (molten alum or what- 

 ever other material might be selected) was poured into the tube. 

 The portion of the liquid which came in contact with the glass solidi- 

 fied almost immediately, forming a cake at the bottom, and the 

 specimen to be compressed was then inserted into the still unsolidified 

 upper portion of the liquid, in such a position that it would be com- 

 pressed in the desired direction, and 

 the rest of the embedding material was 

 then poured in quickly so that it 

 would mingle with that already con- 

 tained in the tube before this had 

 completely solidified. When quite 

 cold and solid, this upper portion, 

 often more or less porous on account 

 of the air bubbles which it contains, 

 was pared away with a knife or filed 

 away by means of a large, coarse, flat file, till the surface was level 

 with the end of the tube. A few smart taps then removed the glass 

 plate from the bottom of the tube thus filled, leaving a flat and 

 polished surface. 



When putting it in the press, it has been found best to place over 

 each end of the tube a piece of stout brass plate. Upon the applica- 

 tion of pressure the copper tube is first pressed into this plate at either 

 end and a very firm and sohd joint is made, the tube becoming con- 

 verted into a box, from which nothing can possibly escape unless the 

 tube itself is ruptured. The copper tube with its contents ready to 

 be squeezed down in the press is shown in the accompanying figure. 

 In some cases larger and heavier copper tubes of various sizes were 

 employed. 



Four different embedding materials were used in these experi- 

 ments, namely, alum, sulphur, fusible metal, and paraffine wax. 

 All these can be rendered fluid at comparatively low temperatures. 

 Kick employed the two materials first mentioned and he also in some 

 cases used shellac and in others stearine. Each of these substances 

 has certain advantages. On the whole, alum and paraffine wax have 

 been found to be the most suitable and in the present series of experi- 

 ments have been used in the majority of cases. 



