^0 
Case 3. — Fine Clays. These include the porcelain and china 
clays, pipe and paper clays with fuller’s earth and other clays 
suited to special uses. 
Case 4 . — Brick clays. Brick clays are the common clays. 
Any clay that can be mol led and will bake to brick without de- 
forming or cracking may be used as a brick clay, guch clays are 
usually very impure. 
Case 5. — Soils. A collection designed to illustrate the forma- 
tion of soils from rocks — and to show the different kinds of soils 
and their compositions. 
Cases 6 and 7. — Briquettes. These are miniature bricks 
made from a great variety of foreign and domestic clays and de- 
signed to illustrate the variety in color, density and other charac- 
ters of bricks made from these clays. 
Case 8. — Terra cotta and foreign bricks. Foreign bricks 
are shown from Mexico, Santo Domingo and La Rabida 
Convent, Spain. These are of the shape known as Roman brick, 
longer, thinner and wider than the ordinary type of bricks. 
Case 9. — Sand and cement. A collection showing all stages 
in the manufacture of Portland cement. A collection showing 
varieties of sand adapted to different uses, such as molding sand 
for molds for metal castings; pure sand for infusible furnace 
hearths and furnace bricks ; sand for the manufacture of glass, 
etc. 
Case 10. — Natural pigments used for paints. The greater 
number are the ochres or clays colored red, yellow or brown by 
oxides of iron and manganese. 
Around the walls of the room are specimens of ornamental 
tiles. 
HALL 78. 
SALTS OF THE ALKALIES AND ALKALINE EARTHS. 
These include besides salts and similar compounds such min- 
erals as asbestos and mica. Here also belong the borates, phos- 
phates, etc., which occur in nature chiefly in combination with 
lime or soda. Besides the alkali and alkali earth compounds, 
sulphur and abrasives may be found in this hall. 
