.1 80 
Corn Stalk Sugar—New Mode for Roofs. 
from time to time, and if there was an appearance of 
feculent particles which would not rise to the surface, 
it was again passed through a flannel strainer. In 
judging when the syrup was sufficiently boiled, a por¬ 
tion was taken between the thumb and finger, and if 
when moderately cool, a thread half an inch long could 
be drawn, it was considered to be done, and was poured 
into broad shallow vessels to crystalize. In some 
cases crystallization commenced in twelve hours; in 
others, not till after several days; and in no case was 
this process so far completed as to allow the sugar to 
be drained in less than three weeks from the time of 
boiling. The reason why so great a length of time 
was required, I have not yet been able to discover. 
There is no doubt but that an improved process of 
manufacture will cause it to granulate as quickly as 
any other. 
In a manual on the subject of cane sugar, prepared 
a few years since, in compliance with a resolution of 
the House of Representatives, some improvements 
were suggested on the usual mode of operation, which 
appear equally applicable to the corn. They are at 
least worthy of trial. The author remarks that 6( Defe¬ 
cation is the great problem of sugar making, and that 
it is one of no easy solution is proved by the unsatis¬ 
factory experience of centuries. We shall venture to 
advance a plan relative to this subject, which is in some 
respects new, and is founded on the view we have 
taken of the chemical composition of cane liquor. The 
cane juice, after having been suffered, by standing, to 
deposit its coarser impurities, should be drawn off to a 
rectangular vat, having a double bottom, and whose 
depth is equal to its diameter; in this vessel it must be 
subjected to a temperature of 208 to 210® F. From 
this vessel, after a repose of about forty-five minutes, 
its clear contents are to be drawn, by an orifice placed 
one inch above the bottom, into a vat of similar con¬ 
struction, whose top is situated four inches above the 
bottom of the first—taking the precaution to pass the 
liquor, in its passage from one vat to the other, through 
a filter of coarse cotton bagging. What remains in the 
vat is then to be drawn off through an orifice, on a line 
with the bottom, and suffered to settle in casks, the 
clear portion being added eventually to the second vat. 
The filtered liquor, in the second receiver, is now 
treated with milk of lime, farmed by adding perfectly 
impalpable slacked lime to water, in the proportion of 
not less than four cubic inches to a gallon, the steam 
being let in previous to the addition of the lime. The 
quantity of temper is to be regulated as follows : after 
the additions of temper, portions of the liquor are ex¬ 
amined, from time to time, by passing it through a fine 
cloth filter, and adding to it, in a wine glass, a tea¬ 
spoon full of clear lime water; so long as a cloudiness 
appears in the liquor, on the application of this test, 
more milk of lime must be added. The heat must be 
carried to 210° F., when the steam must be cut off, and, 
after a repose like that above described, it is run off by 
means of an orifice, one inch above the bottom, until 
it begins to appear cloudy, when this orifice is closed, 
and another, situated on a level with the bottom, is 
opened, and the remainder is run off into a tub or bar¬ 
rel to settle for future decantation. The defecated 
liquor is made to traverse a bagging filter, as before, on 
its way to a general reservoir near the grande, and 
which should be capable of holding one thousand gal¬ 
lons. Sulphuric acid, diluted with twenty times its 
weight of water, or tartaric acid, dissolved in ten times 
its weight of water, is added, from time to time, to this 
reservoir, in quantities sufficient to maintain its con¬ 
tents, as nearly as possible, in a state of neutralization, 
or in such a condition that there will be no alkaline 
reaction on paper stained with yellow by a strong de¬ 
coction of turmeric. 
The reasons for the foregoing plan are the following. 
Heat alone is sufficient for the separation of the albu¬ 
men, and a large portion of the green fecula. The 
first heating, therefore, coagulates the albumen com¬ 
pletely, the greater part of which will rise to the sur 
face in a scum, more or less tenacious, bringing along 
with it a part of the precipitated fecula; while another 
portion of these impurities then falls to the bottom, 
along with insoluble earthy matters, pieces of cane, &c. 
And on being transferred to the second vat, the quan¬ 
tity of lime required for rendering insoluble the bal 
ance of the coloring matter in the juice, is greatly re¬ 
duced, while its mischievous influence in rendering 
albumen soluble is avoided, since the principal part is 
already removed. The filters collect those flocculi 
which had escaped the process of subsidence; and the 
addition of sulphuric acid, or of tartaric acid, removes 
from the defecated liquor all excess of lime which it 
may contain, and the insoluble precipitate of sulphate 
of lime besides on the bottom of the general reservoir, 
without going forward to injure the kettles by the for¬ 
mation of a thick crust. 
It will be at once apparent, wherein the present 
method of defecation has advantages over that where 
steam vats are employed, since by that plan a large 
portion of the albumen was rendered permanently solu¬ 
ble by the lime employed for throwing down the green 
fecula; and besides, no measures were taken for get¬ 
ting rid of the superfluous alkali remaining in solution, 
after the defecation was completed—the alkali being 
left to enter into union with the sugar, and by its sub¬ 
sequent action upon it in the kettles, to convert it into 
gum.” 
(Remainder in next number .) 
Cheap Roofs. —The simple mode of roofing out¬ 
houses by nailing thin boards on light rafters may be 
introduced to very great advantage, particularly in the 
country. It is only to subject the boards, before using, 
to the action of fire, by way of thoroughly seasoning 
them. Nail them on immediately, and cover them with 
sheathing paper and a dressing of tar; and a covering, 
almost for a lifetime, may safely be calculated upon. 
The rafters, three inches deep, one and a half thick; 
the boards half an inch thick, straightened on the edges 
and closely nailed. 
The following composition for covering such a roof 
was employed at Wickham twenty years ago, and is at 
this present time as good as when first laid. The roof 
is nearly flat, having a run of one inch only to the foot, 
the boards being securely nailed and covered with a 
course of sheathing paper, such as is used under the 
copper-sheathing of ships, made fast by small flat-head¬ 
ed nails. To eight gallons of common tar, add two 
gallons of Roman cement, five pounds of resin, and 
three pounds of tallow; boil and well stir the ingredi¬ 
ents, so as thoroughly to incorporate them, and lay on 
the roof while hot, with a brush, spreading it very 
evenly; then sprinkle it while hot with sharp sifted 
sand, and when cold, tar and sand as before; after 
which, a single coat of tar once in five or six years will 
preserve the roof for an age. 
To the above may be added, an incombustible im¬ 
penetrable wash, prepared according to the following 
directions. Slake stone lime with hot water in a tub, 
covering it to keep in the steam; pass six quarts of it 
through a sieve, it being in the state of fine dry pow¬ 
der, and add to it one quart of fine salt and two gallons 
of water, boiling and skimming it. To every five gal¬ 
lons of this boiled mixture, add one pound of alum. 
