[April 27,1872. 
SGI 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
that the plant “ might be employed like the nettle 
(Urtica) as a counter-irritant in epilepsies and dis¬ 
eases requiring stimulating applications. The plants 
of this family furnish generally a stimulating and 
highly acrid oil, and they should be examined.” A 
reference to the virulent nature of the plant is made 
at p. 252, Yol. II. of the present series of this 
Journal. 
Another very virulent stinging plant which has 
been cultivated at Kew is the Urtica (jigas, or tree- 
nettle of New South Wales. It grows to a height 
of 100 or 150 feet, with a tapering trunk which 
sometimes runs up to nearly 100 feet before branch¬ 
ing. The tree is remarkable for the buttresses 
which are formed with great regularity around its 
base. It bears dark green cordate leaves, fiom 
twelve to fifteen inches wide, the stings upon which 
are most formidable and even dangerous. The tree 
was introduced to Kew by Allan Cunningham in 
1828, and grew to a height of about six feet, but it 
died, perhaps from the neglect of the men under 
whose charge it was placed, and who probably had 
a natural dislike to it, owing to its excessively dan¬ 
gerous character, and from the fact of several of 
them having been stung by it. We believe the 
plant has never since been introduced. The curator 
was also a victim to this plant, having been stung 
in the hand; and he describes the effect as one of 
continued pain in the region of the arm-pit for six 
weeks or more, which pain became more sensible on 
the hand being wetted. Another species, Urtica 
pliotinifolia, likewise a tree abundant in the Cla¬ 
rence and Richmond brush forests is also very poi¬ 
sonous, as are some of the Indian- species, such as 
Urtica heterogJujlla, etc. 
A NEW SOURCE OF POTASH SUPPLY. 
BY HERBERT HAZARD. 
The present sources of the potash supply are rapidly 
failing-; every year the area of the supply becomes 
smaller, and the product, in consequence of this and the 
increased demand, becomes more and more expensive. 
At the rate the country has been settled and the woods 
destroyed for the past ten or fifteen years, the source of 
supply in the United States will, in a comparatively few 
years, almost entirely fail. States which, a few years 
since furnished large quantities of ashes, now furnish 
none; wood has become too valuable in the arts to he 
burned even for fuel. The people as well as the Gl-overn- 
ments, in the older States, have commenced to discuss 
the ways and means of perpetuating their hard-wood 
forests, both as a protection to the land and for mecha¬ 
nical purposes. Soft woods do not yield enough of the 
salts to pay for working their ashes; hence we are 
driven to the newly-settled portions of the West and 
North-west for our present supply, the largest portion of 
which comes from Michigan and Wisconsin, where the 
trees are cut down and burned as the readiest means of 
clearing them from the land. But as the population of 
these States is rapidly increasing, and railroad lines are 
being proportionately extended, the forests are brought 
into more direct communication with the lakes and large 
cities, thus finding a market for their timber ; and the 
saw-mill will then use up all the surplus trees, which will 
go into commerce as lumber instead of ashes, as at 
present. These causes will very much reduce, if not 
wholly terminate, the present supply from the North¬ 
western as they have from the Eastern States. 
The forests of the Old World, by care and cultivation 
still furnish large quantities of potash, but never suffi¬ 
cient for home consumption, therefore this source of 
supply is not available to us; again, the demand for 
these salts is constantly increasing, both in medicine and 
in the arts, two more very cogent reasons why a never- 
failing source of supply should be secured. 
This, it seems, can be accomplished in the following- 
manner :—throughout the Western States large quan¬ 
tities of com are produced, the cobs of which are now 
considered of little or no value, yet they may share the 
same fate as many substances which, though formerly 
considered worthless, have become new mines of wealth 
through the aid of chemistry. By the following assays 
and comparisons, I propose to demonstrate their value 
to pharmacy and the arts. 
One hundred parts air-dried cobs yield, after drying at 
212° E., the following results:— 
Silica, Charcoal, 
Cobs. 
Ashes. 
KC1. 
EACO 3 Lime, Iron. 
Loss. 
1 st, 
91-70 
1-120 
•820 
•750 
•140 
•230 
2 d? 
90-95 
1-040 
•805 
•745 
•180 
•115 
3d, 
92-85 
1-015 
•840 
•755 
•245 
•005 
4th, 
90-94 
1-115 
•830 
*795 
•300 
•020 
Averaging,!) T61 
1-072 
•824 
•762 
•217 
•093 
Or, one hundred parts dried at 212° F., give the follow¬ 
ing results:— 
Silica, Charcoal, 
Ashes. 
KC1. 
I1-2C03 
Lime, Iron. 
Loss. 
1 st, 
1-221 
•894 
•818 
T50 
•253 
2d, 
1.143 
•885 
•819 
•192 
•132 
3d, 
1-093 
•904 
•834 
•252 
•007 
4 th, 
1-226 
•913 
•874 
•329 
•030 
An average 
of 1-171 
•899 
•836 
•230 
T05 
The cobs were incinerated as thoroughly as possible 
without the use of nitric acid or other oxidizing agent, 
the presence of silica impeding the complete combustion 
of the charcoal. The ashes were assayed by exhausting 
them with water and filtering off the soluble portion, 
leaving a residue on the filter consisting of silica, char¬ 
coal, carbonate of lime, and a trace of iron. The filtrate 
was supersaturated with muriatic acid, evaporated to 
dryness and redissolved in acidulated water, leaving an 
additional quantity of silica, which was added to the 
first portion and weighed with it. The solution was then 
evaporated to dryness and weighed as chloride of 
potassium, and from this weight the carbonate -was 
calculated. 
In volume iv. of Watts’s ‘ Dictionary of Chemistry,’ the 
results of some analyses by Hoss are given, from which 
it appears that ash, oak, elm and willow, which of our 
most common forest wood are richest in potash salts, 
yield respectively -71, ToO, 3 - 90 and 2-85 parts carbonate 
potash in one thousand of wood. 
The average yield of one thousand parts of cobs, as 
shown by the tables above, is 7’62 parts carbonate 
potash, or nearly twice as much as the best specimens of 
wood, and from a material which can fill its full measure 
of usefulness for other purposes before it comes into the 
hands of the manufacturer of potash. 
But the questions may be raised, how can these cobs 
be collected in quantities sufficiently large to pay for 
working them, and is the supply sufficiently large to be 
of any commercial importance P The first question is 
easily answered, for they are already collected at the 
shipping-points of the growing districts, where large 
shelling-mills, capable of running through 500 bushels 
of ears of corn an hour, are established; here, then, are 
the places where a supply of cobs may be procured. 
The figures below will show with what rapidity they 
accumulate. 
A bushel of corn weighs 70 pounds on the cob; a 
bushel of shelled coni weighs 56 pounds, leaving a 
balance of 14 pounds cobs to the bushel; and a mill, 
shelling 500 bushels an hour, turns out 7000 pounds cobs 
an hour, or equal to 70,000 pounds per working day of 
