for the works of watches, as also watch chains and ornaments. For
certain parts, such as journals of engines, lathe-head boxes, pinions,
and running gear, it has proved itself superior to all other metals.

Hulot, director of the Imperial postage stamp manufactory in Paris, uses
it in the construction of a punching machine. It is well known that the
best edges of tempered steel become very generally blunted by paper.
This is even more the case when the paper is coated with a solution of
gum arabic and then dried, as in the instance of postage stamp sheets.
The sheets are punched by a machine the upper part of which moves
vertically and is armed with 300 needles of tempered steel, sharpened in
a right angle. At every blow of the machine they pass through the
holes in the lower fixed piece, which correspond with the needles, and
perforate five sheets at every blow. Hulot now substitutes this piece by
aluminum bronze. Each machine makes daily 120,000 blows, or 180,000,000
perforations, and it has been found that a cushion of the aluminum alloy
was unaffected after some months' use, while one of brass is useless
after one day.

Various formulae are given for the production of alloys of aluminum, but
they are too numerous and intricate to enter into here.

* * * * *




DETERMINATION OF POTASSA IN MANURES.

By M.E. DREYFUS.