522 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [December 30,1871. 
its vesicating properties; but it bad previously been 
described by Fabricius as a native of the Cape of 
Good Hope. Dr. Harris, of Massachusetts, found 
it equally efficient as a vesicatory with any other 
species of the genus. The following is Harris’s 
graphic description of this insect:— 
“ There is a large blistering-beetle which is very 
common on the virgin’s-bower ( Clematis virginiana) 
a trailing plant, which grows wild in the fields and is 
cultivated for covering arbours. I have sometimes 
seen this plant completely stripped of its leaves by 
these insects during the month of August. They 
are very shy, and when disturbed fall immediately 
from the leaves and attempt to conceal themselves 
among the grass. They most commonly resort to 
the low branches of the clematis, or those that trail 
upon the ground, and more rarely attack the upper 
parts of the vine. They also eat the leaves of various 
kinds of Ranunculus or buttercups, and, in the 
Middle and Southern States, those of Clematis viorna 
and crispa. This beetle is the Cantharis marginata 
of Olivier, or margined Cantharis. It measures T % 
or -j~j of an inch in length. Its head and thorax are 
thickly covered with short grey down, and have 
a black spot on the upper side of each; the wing- 
covers are black, with a very narrow grey edging; 
and the under side of the body and legs are also 
grey.” 
This is one of the species commonly employed in 
the United States of America, and is enumerated as 
such in Wood and Bache’s ‘ Dispensatory.’ 
Ash-colourf.d Blister-fly, Lytta clnerea, Fabr. 
—Fabr. Syst. ii. p. 80 ; Brandt and 
B-atzb. ii. t. xviii. f. 13 ; Pall. Ic. 
p. 08. t. E. f. 30 ; Leconte, Syn. p. 330. 
Lytta Fabricil, Lee.; Durand, Journ. 
Phil. Coll. Pliarm. ii. 274. f. 5; 
Wood and Baclie, U.S. Disp. (1807), 
p. 200; Harris, Injurious Insects, 
etc. (1802), p. 138. f. 03; Packard’s 
Guide, p. 480. f. 453 a. 
Found in the Northern and Middle 
States of North America. 
The asli-coloured Cantharis closely 
resembles the potato-fly in figure and size, but differs 
from it in colour. The elytra and body are black, 
without the yellow stripes that characterize C. vittata, 
and are entirely covered with a short and dense ash- 
coloured down, which conceals the proper colours of 
the insect. The feelers are black, and the first and 
second joints are very large in the male. This spe¬ 
cies also inhabits the potato plants, and is occa¬ 
sionally found on other plants, as the English bean 
and wild indigo. It is a native of the Northern and 
Middle States. Illiger in 1801 discovered its vesi¬ 
cating properties, but Dr. Gorham was the first to 
call public attention particularly to the subject, in a 
communication addressed, in the year 1808, to the 
Medical Society of Massachusetts. 
The most destructive kind of Cantharis found in 
Massachusetts is of a more slender form than C. 
marginata, and measures only to 6 of an inch 
in length. Its antennae and feet are black, and all 
the rest of the body is ashen-grey, being thickly 
covered with a very short down of that colour. 
Hence it is called C. clnerea, or the ash-coloured 
Cantharis. When the insect is rubbed, the asli- 
coloured substance comes off, leaving the surface 
black. It begins to appear in gardens about the 
20th of June, and is very fond of the leaves of the 
English bean, which it sometimes entirely destroys. 
It is also occasionally found in considerable numbers 
on potato vines; and in Cambridge, Massachusetts, 
it has repeatedly appeared in great profusion upon 
hedges of the lioney-locust, which have been entirely 
stripped of foliage by these voracious insects. They 
are also found on the wild indigo-weed. 
In the night, and in rainy weather, they descend 
from the plants, and burrow in the ground or under 
leaves and tufts of grass. Thither also they retire 
for shelter during the heat of the day, being most 
actively engaged in eating in the morning and even¬ 
ing. About the 1st of August they go into the 
ground and lay their eggs, and these are hatched in 
the course of one month. The larvae are slender, 
somewhat flattened grubs, of a yellowish colour, 
banded with black, with a small reddish head and 
six legs. These grubs are very active in their mo¬ 
tions, and appear to live upon fine roots in the 
ground; but I have not been able to keep them till 
they arrived at maturity, and therefore know nothing 
further of their history (Harris). 
(To be continued.) 
Fig. 11 .—Lytta 
esnerea. 
filters for JSfobMttj. 
CHEMICAL NOTES TO THE PHARMACOPOEIA. 
BY WILLIAM A. TILDEN, D.SC. LOKD. 
DEMONSTRATOR OF PRACTICAL CHEMISTRY TO THE 
PHARMACEUTICAL SOCIETY. 
C Potassje Carboxas. — [§ K 2 CO s with about 10 per 
cent, of water of crystallization. 
Obtained from commercial pearlasli, the product 
of the lixiviation of wood-ashes, by treating the 
pearlasli with its own weight of distilled water, and 
evaporating the solution so formed to dryness, while 
it is kept briskly agitated.] 
Wood-ashes still supply us with all the carbonate 
of potassium required in so many great manufac¬ 
tures, notwithstanding that more than one attempt 
lias been made to procure that salt from other and 
especially mineral sources. 
Of course, carbonate of potassium does not exist 
in the tissues of the plants from which it is obtained, 
but is the result of incinerating the various organic 
salts present therein. These salts (tartrates, citrates, 
malates, oxalates, etc.) contain at least one atom of 
carbon to every atom of potassium, and by burning 
them in the air they leave a residue of carbonate. 
It was, in fact, called salt of tartar, from having 
been formerly prepared from the cream of tartar, or 
acid tartrate of potassium. Wood-asli contains 
varying proportions of other salts, such as the sul¬ 
phate and chloride of potassium, as w r ell as silica. 
These are for the greater part got rid of in the pro¬ 
cess of lixiviation, shortly described in the Phar¬ 
macopoeia. 
Carbonate of potassium is recognizable by its de¬ 
liquescence, by effervescing with acids, and by form¬ 
ing with hydrochloric acid a solution which with 
percliloride of platinum gives a yellow precipitate of 
the double chloride, PtCl 4 . 2 KC1. It always con¬ 
tains traces of silica, sulphate and chloride. A very 
pure carbonate can be readily made if required by 
heating crystals of the bicarbonate to dull redness. 
[§ Test. 8'3 grams require for neutralization at 
least 98 cubic centimetres of the volumetric solution 
