Green-Mountain freeman. [volume] (Montpelier, Vt.) 1844-1884, 1880-09-15
NltrO-GlYcerine.

The Boston Herald's correspondent lat
north Adams. says: About one hundred
Yards beyond the west shaft Of the Hoosac
tunnel is to be seen a board fence sur
rounding about ten acres of ground with
the announcement, 'Nitro-glycerine works i
dangerous; no visitors admitted" A drive
leading between two rows of buildings
brings the visitor to the acid house, u
well ventilated building, $50 feet long
Here are eleven stills. each seven feet long
and two feet in diameter. Under these a
llght' slow fire burns, which is carefully
attended to, for the temperature must be
Kept moderate. In each of these stills is
put a charge of nitrate of soda and of sui
phuric acid. A stoneware pipe conducts
the gases, at II temperature of about $50
degrees Fahrenheit, from each still into
stone receiver or condenser, or. rather a
series of condensers connected by stone-
ware pipes ranged on platform three feet
above the ground. Into three of these sui
phurlc acid is poured, and the fourth is
empty. The nitrous vapor passes from a
still to the first condenser. where portion
OF it, forming as 1t condenses. nitric acid
is taken up by the sulrhuric acid; the re-
malnder passes on to the second, third and
fourth condensers, though very small
portion is left to pass into the last, which
only requires to be emptied once a month
1t takes about twenty-four hours for the
still to complete conversion of its contents
into nitric acid at the end of which time
the resultant mixture, about six hundred
pounds, is run off into carboys, twelve of
these being filled from three stills About
one hundred carboys are generally kept in
stock, as the acid does not spoil when kept
closed. These carboys are emptied into a
soapstone tank having capacity of eigh-
teen carboys. and an iron pump, connected
with the main leading from the blowers in
the engine house, is inserted into the acid,
causing current of air to agitate it, so as
to remove the nutritious fumes, mix it
thoroughly and bring it all to uniform
strength. Fortunately this was affected
by removing the acid into a glass vessel
containing about forty gallons, and it re-
CURED boiling for hours; the mode now
practiced requires only five minutes, and
the risk of fracture of glass vessel in a
sand bath is avoided. The acid is then
carried into Il converting room, about 100
feet long and we'll lighted where il is di-
vided among l6 stone pitchers, arranged
/ 80 hi''S "OObSu JittCCI III Jllc Ctu-
tire and at the end of the room, and these
troughs are now filled with ice cold water,
or ice or SALT so us to rise within four
inches of the top of the jar. On the shelves
above the troughs are arranged glass jars,
one to each stone pitcher Into each of
these glass jars chemically pure glycerine
Is poured, aud this, by means of syphon,
with rubber tube attached about two feet
long, falls, drop by drop, into the CORE
spending pitcher of mixed sulphuric and
nitric acids. Immediately below the shelf
on which the glycerine jar stands is two
and one-fourth inch iron pipe, which brings
IA current of cold air from the receivers
connected with the two blowers above
mentioned. This current of air is dis.
trlbuted to each jar while the acid and
glycerlne are mixed by rubber pipe, to
which is attached glass tube sixteen
inches long with one-quarter of an inch
bore. During the hour and half or two
hours that the glycerne takes to run of
into the pitchers the greatest care and at.
tention are requisite. The three men
whose duty it is TO attend to the mixing
process have each row OF pitchers t.
watch. walking the whole time up and
down beside them, with the thermometer
ip hand, and, as the nitrous fumes rise
from the forming nitro-gycerne, they slil
the mixture with the glass tube before
mentioned in pitcher that may be giving
out too violent fumes. Sometimes this is
caused by the glycerine running little
freely, which fires the mixture, wastes the
glycerine, forming oxalc acid, and de
velops unpleasant vapors.