CERTAIN IMPROVEMENTS IN PREPARING OR MANUFACTURING CERTAIN "SUBSTANCES, SO AS TO PRODUCE BARILLA OR SUBSTITUTE FOR BARILLA
Year: 1829

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MAC LEOD, Esquire, of Westminster, Surgeon on the Madras Establishment,
send greeting.
WHEREAS His present most Excellent Majesty King George the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Eleventh day of August, in the tenth year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
John Mac Leod, His special licence, that I, the said John Mac Leod, my
executors, administrators, and assigns, or such others as I; the said John
Mac Leod, my executors, administrators, or assigns, should at any time
agree with, and no others, from time to time and at all times during the
term of years therein expressed, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, and in all His Majesty's Colonies and Plantations abroad, my
'Invention of "CERTAIN IMPROVEMENTS IN PREPARING OR MANUFACTURING CERTAIN
"SUBSTANCES, SO AS TO PRODUCE BARILLA OR SUBSTITUTE FOR BARILLA;" in which
'said Letters: Patent is contained a proviso obliging me, the said John Mac Leod,
by an instrument in writing under my hand and seal, particularly to describe
and ascertain the nature of my said Invention, and in-what manner the same
is to be performed, and to be enrolled in His said Majesty's High Court of
Chancery within two calendar months next and immediately after the date of.
the said recited Letters-Patent, as in and by the same, reference being there-
unto had, will more fully and at large appear.

page_text: NOW KNOW YE, the mode of preparing the patent barilla or substitute
for barilla.
Travelling along the coast of Coromandel at certain seasons of the year, the
ground in many places is observed to be covered with a white efflorescence.
On examination, it-will be found to consist chiefly of murate and sesquicar-
bonate of soda. These substances are collected by the natives, and used by
them for a variety of purposes. The ground on which this effloresence appears
is never covered with verdure. The soil is a deep sand, with a mixture. of
clay, carbinate of lime, &c. The clay contains, as it generally does, some
oxyd of iron.
Whole fields on the west side of the Great Pulicate Lake,
forty or fifty miles north of Madras, are of this description. Carbonate (sesqui-
carb.) of soda is met with only on the surface, and it is found in greatest
abundance a few weeks after, the periodical rains have ceased. The natives
begin collecting it in March, and continue to do so during the hot weather
that succeeds. The saline-crust is scraped from the surface, mixed with sand
and clay, washed in water so as to separate some of the insoluble matter, and-
the watery solution is evaporated to dryness: The residuum thus obtained is
the karum of the bazars, and is the only preparation hitherto made or used in
India of these materials: This karum contains-from-4-to-6-or 8 per cent.
of soda, and the rest: consists of carbonic acid, sand, clay, muriate of soda,
decomposed..vegetablé, matter, and occasionally other impurities. : Various
attempts have been made to introduce this substance into our manufactories,
and with this view consignments of it have at different times been sent from
Madras, but the nature and quantity, of its impurities effectually excluded it..
Some years ago it: occurred to, me, that if it were divested of some of its
insoluble matter;. and. submitted to the action of fire, so as to free it from a
portion of carbonic acid, decomposed vegetable matter, water, sulphur, and
:other, volatilizeable impurities, it might become an article of considerable
importance. I conceive that if the karum were treated in this manner, and
fused in a reverberatory or other furnace, it might be converted into a sub-
stance resembling barilla, which would be found a perfect substitute for that
article. This idea I soon after put in practice; but my first attempts were
unsuccessful. The materials above mentioned. being fused in a reverberatory
furnace became a mass of green glass,-in consequence of their containing a
quantity of selicious matter of which they had not been sufficiently divested.
It therefore became necessary to get rid of this admixture by more careful
solution, and evaporation to dryness, as already mentioned. These operations
being performed with sufficient care, the residuum underwent the action of
fire without any sensible portion being converted into glass, and the fused

page_text: mass being withdrawn and cooled resembled very fine barilla in its most
essential properties, and in fact passes current in the London and Antwerp
markets as barilla of a superior quality.
In witness whereof, I, the said John Mac Leod, have hereunto set my
hand and seal, this Fifteenth day of August, in the year of our Lord
One thousand eight hundred and twenty-nine.