65 Short Papers and Notes. 
completed. The surface of the stone is covered to the desired 
degree with a solution of the fluate by means of a brush, sponge, 
or hand-pump. Another application is made the next day, and a 
third one the day after. As a general rule, it requires three appli- 
cations. The hardening takes place at once, and upon the third 
application becomes perfect. here are several soluble fluates, 
each of them having its peculiar properties. One darkens the 
colour of the stone, another whitens it, another preserves the 
original colour, and others colour the stone indelibly. The 
colouring fluates mostly employed are those of iron, which give a 
brown tint, and those of chromium and copper, which give two 
greens of different shades. Fluatation is applied to old structures 
as well as to new ones, and is a true means of preserving the edi- 
fices that have been bequeathed to us. After the stone has once 
been fluated, it becomes so hard that it can be treated like 
marbles and porphyries. Upon applying the coloured fluates 
along with a subsequent polishing, very remarkable decorative 
effects are obtained, inasmuch as the intimate structure of the 
stone is brought to light, and the nodules, veins, and fossils are 
delineated in different tints. After the stone has been fluated, it 
can easily be rendered impermeable, and, as it is not attackable 
by ordinary liquids, it may be used for making tables, sinks, 
baths, and reservoirs for a host of liquids, such as wine, oils, . 
alcohols, molasses, etc. Fluatation is applied in the same way to 
cement, mortars, stuccoes, ete., provided they are more or less 
calcareous. It renders the alkalies of cements insoluble, and 
thus, after a washing with water to remove the excess of fluate, 
permits of a coating of paint being applied.—Za Genie Civil, 
Collecting Microscopic Alga. 
Take waxed paper (from cakes of soap, etc.), and punch holes 
slightly smaller than the largest covers, then wrap the paper about 
the slides in such a way as to bring the holes in the middle on 
each slide. On suspending the slides, good mounts can be 
obtained. Surround it with a ring, place on another slip or cover- 
glass, and it is ready for observation. 
Snout=Moths, 
These insects fly near the ground, and suddenly settle and 
disappear as if by magic. Their wings are broad and ample in 
proportion to their size ; but when they are folded, the moth looks 
so much like a large grass seed that it mostly escapes detection. 
erald=Moth (Scoliopteryx libatrix i) 
This beautiful insect occurs in great profusion in some of the 
