October 8, 1870.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
285 
tlie blood, muscles, tissues, as well as of all organs, 
and, in tlie latter form, of the food. Sometimes 
the part they take is very decided; it is only by 
their aid that the nutritive substances in the food of 
man, and in the fodder of animals, acquire the capa¬ 
bility of serving for the maintenance of organic pro¬ 
cesses and, consequently, these salts should always 
be taken into account in the explanation of those 
processes. 
However, the length to which these papers have 
now extended precludes any more detailed conside¬ 
ration of the chemical relations of salts to the or¬ 
ganic processes for the present, and I must reserve 
this subject for a future opportunity.— Proceedings of 
the Roy. Bavarian Academy of Sciences, 1869, ii. 4. 
PREPARATION OF CANTHARIDATE OF POTASH. 
The following directions are given by MM. Delpech 
and Guicard:—Dissolve with a gentle heat 2 grams 
of cantliaridine in 150 grams of alcohol; add l'G 
grams caustic potash dissolved in a little distilled 
water. The liquid immediately assumes the form of 
magma, and the alcohol is to be separated by filtra¬ 
tion and pressure. Ninety-eight parts of cantliaridine 
give 163 parts cantliaridate. 
To prepare vesicating taffetas, make a solution 
consisting of gelatin 2 parts, water 10 parts, alcohol 
10 parts, cantliaridate of potash 0'2 part, and glyce¬ 
rine as much as may be required. Tliis mixture is 
to be spread over thin sheets of gutta-percha with a 
brush, so that each square decimetre may contain 
one centigram of cantliaridate. These taffetas must 
be moistened with water before being applied. Vesi¬ 
cation will be produced in about six hours.— Jo urn. 
de Pharm. et de Chim. 
THE PRODUCTION OF IODINE AND BROMINE. 
BY W. 11. CHANDLER. 
To Scheele the world is indebted for the first intima¬ 
tion of the elementary existence of fluorine and chlorine, 
he having in 1771 referred the action of sulphuric acid 
upon fluor-spar to the freeing of a distinct acid from the 
mineral, though whether fluorine has, even up to the pre¬ 
sent day, been isolated, is a matter of great doubt. In 
1774 the same chemist isolated chlorine. In 1811 Cour- 
tois separated iodine from the waste liquor in the manu¬ 
facture of soda ash from seaweed. This was followed by 
the discovery of bromine in the bittern of sea-water by 
Balard in 1826. The isolation of these four closely- 
allied elements from their compounds was thus included 
in a century, and the application of them to economical 
purposes, to any extent, has been accomplished since the 
beginning of the present century. Their close relationship, 
their physical properties and their chemical affinities, 
which are nearly in an inverse proportion to their che¬ 
mical equivalents, induce the supposition that they are 
modifications of the same element. 
The isolation of chlorine, bromine and iodine from 
their compounds with the alkalies, is accomplished with 
equal facility. But the abundant store of the former in 
the enormous deposits of salt throughout the world and 
in solution in the ocean and inland seas, forms a striking 
contrast to the rarity of the two latter halogens. In 
combination witli silver, bromine and iodine are foimd 
in some rare ores in Mexico and South America. Chatin 
claims to have detected iodine in rain-water, though in 
very minute quantities, and even in the atmosphere. In 
sea-water traces of it have been uniformly detected 
though not in quantities sufficient for quantitative esti¬ 
mation. Bromine exists in slightly larger quantities 
and, associated with iodine and chlorine, is found in the 
water of the ocean and inland seas, the various mineral 
and saline springs and in salt deposits throughout the 
world. 
According to Von Bibra, the amount of bromine in the 
Atlantic Ocean, in one United States gallon, is 24 grains; 
in the Dead Sea, examined by Herapath, 121 • 5 grains; 
in the dried residue of the Mediterranean, US per cent.; 
in the mineral springs of Ivreutznach, Ure found 10 8 
grains; in Kissingen water, determined by Kastner, 
0‘44 grains; at Tenbury, in Worcestershire, examined 
by Dr. Ure, as much as 12 5 grains ; and at Arnstadt, ac¬ 
cording to Hartung, 13 • 6 grains. Iodine occurs in far 
less quantities, from mere traces to 2-2 grains per gallon, 
this latter quantity being found in the iodine spring at 
Halle. 
In the United States, both bromine and iodine have 
been detected in the various saline and mineral springs. 
Iodine was first detected in this country, in the Saratoga 
Spring waters, by Drs. Usher and Steel, in 1830, and 
bromine in the same waters by Dr. A. A. Hayes, and in 
the salines of Onondaga by Professor B. Silliman, in the 
same year. The quantity of bromine in the spring 
waters of Saratoga county, determined by Professor 
Chandler, reaches 3'63 grains per gallon in the water of 
one of the artesian wells, the largest amount of iodine 
found being 0-2 grain; but in America, as in Europe, 
it is in the salines that the quantity of these substances 
becomes of economical importance, and in a brine of the 
Saginaw valley, Dr. Chilton found 7'6 5 grains of bromine; 
at Tarentum, Pa., 6 grains bromine and 4 grains iodine 
were reported by Stieren ; in the Salina brine analysed 
by Professor Goessmann, however, only P36 grains of 
bromine per gallon are reported. 
Besides these various sources, iodine has been detected 
in the soda deposits of Peru, in the ashes of sponges, and 
in the ashes of the Spanish barilla plants. Cod-liver 
oil is said to owe some of its medicinal properties to a 
trace of iodine. Though the distribution of bromine and 
iodine is thus very general, yet owing to their existence 
in such comparatively minute quantities, the sources of 
our commercial supply are much more restricted. 
Up to the beginning of this century the alkalies of 
commerce were derived from the ashes of plants, and the 
burning of sea-weeds was an important industry, espe¬ 
cially in Great Britain and Ireland. 
The amount of ashes of sea-weed, the so-called kelp, 
reached its maximum production in 1800, when 20,000 
tons were collected. To produce this, 400,000 tons of 
wet weed were burned. From this time, owing to the 
removal of the import duty and to the introduction 
of the manufacture of soda-ash from common salt, the 
trade declined. But the discovery of iodine in the mother- 
liquors of kelp salts, somewhat revived the manufacture, 
—and it is to this source alone that the total supply of 
iodine in commerce is due. The high price stimulated 
the business, and, in a few places in New England, 
iodine factories were established. These latter, however, 
were soon abandoned, the weed upon our coast being of 
poor quality. The process of separating the iodine is 
exceedingly simple, being nearly analogous to that for 
the isolation of chlorine. The ashes are leached with 
water, and the various crystallizable salts of potash and 
soda are separated by concentration. Carbonates, sul¬ 
phates and chlorides of potash and soda are thus re¬ 
moved, leaving in solution, sulphite, hyposulphite and 
some carbonate of soda, together with the iodides and 
bromides. By the addition of sulphuric acid the first 
three salts are decomposed, and the sulphate of soda pro¬ 
duced is removed by crystallization. The concentrated 
mother-liquor is acidulated with sulphuric acid, and after 
the addition of binoxide of manganese, the iodine and 
bromine distilled off. The reaction may be represented 
thus:— 
Nal + Mn0 2 + 2 (HO, S0 3 ) 
= NaO,SO a + Mn O, S 0 3 + 2HO + I. 
The bromine of commerce was derived mostly from 
