September 21,1972.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
223 
dered mustard are due to a volatile oil obtained in dis¬ 
tilling black mustard with water. But it fell to 
Will to determine the nature of this oil. He showed 
that the essence of mustard contained, combined with 
sulphur and cyanogen, an organic radical known under 
the name of allyl, and already met with in other sub¬ 
stances ; for instance, in essence of garlic, where it is 
combined with sulphur under the form of sulphide of 
allyl. AVhile studying the action of iodide of phosphorus 
upon glycerine, Berthelot observed the formation of a 
substance in which this radical was united with iodine to 
form iodide of allyl; this quickly gave rise to the idea 
of the synthesis of the essence of mustard by the reaction 
of a metallic sulphocyanide upon the iodide of allyl. In 
fact, by distilling the iodide of allyl with sulphocyanide 
of potassium, essence of mustard was produced possessing 
all the properties characteristic of that obtained from 
the plant, and a large proportion of commercial essence 
of mustard is made in this manner. 
# In. connection with this subject I would briefly men¬ 
tion another synthesis which has some interest, although 
but a slight one for therapeutists. In the organism of 
the Cochlearia Armoracia is produced an oil which the 
pharmacist utilizes to a certain extent in the spirit of 
horseradish. This oil has been ascertained in recent 
researches to have a constitution analogous to that of 
essence of mustard. It is sulphocyanide of butyl, a 
compound which it is easy to prepare artificially. 
In the presence of these conquests, are we not right 
in expecting that the more important medicaments, 
which at present can only be extracted from the plants, 
will soon be prepared synthetically by chemists, and 
that even if they are not produced directly from the 
elements, at least it will be possible to obtain them by 
the modification of other substances, so that they will 
be procurable more easily and in larger quantity than 
by the. present methods F However this may be, the 
foregoing examples are sufficient to indicate in how many 
cases the study of the changes undergone by organic 
bodies has been the origin of new, simple and less costly 
methods for the preparation of substances of which the 
curative properties have been demonstrated by experi¬ 
ence. It would have been singular if, in traversing these 
tortuous paths in the domain of chemistry, the searcher 
had not also encountered some new compounds of which 
it sufficed to study the properties and recognize in them 
valuable therapeutic agents. 
It is not necessary to seek far for examples of the pro¬ 
gress of therapeutics in this sense due to the develop¬ 
ment of organic chemistry. The products of dry dis¬ 
tillation vary not only with the nature of the substance 
distilled, but also with the temperature used in the 
operation. The decomposition is thus very varied, espe¬ 
cially when the substances employed are complex mix¬ 
tures of different compounds. Among the numerous 
products so obtained from wood, creasote, discovered by 
lieichenbach in the products of distillation of beech- 
wood must be mentioned first.. That chemist did not fail 
to appreciate its strongly antiseptic properties, as is in¬ 
dicated by the name he assigned to it. The antiputres- 
cent action of creasote was so indubitable that, from the 
time of its discovery, it has been the object of an active 
manufacture; nevertheless, it has not been much em¬ 
ployed in medicine, it being used principally for the 
the sake of its antiseptic properties. By the side of creasote 
was soon placed carbolic acid, an analogous body dis¬ 
covered. by Runge in coal-tar. Possessing the same 
properties as creasote, carbolic acid has the advantage 
of. being crystalline and presenting more definite che¬ 
mical properties; it is easily prepared in a pure state 
and its purity assured, especially when, as is frequently 
the case, the well-crystallized sulphocarbolates derived 
from this acid are used. Besides the price of carbolic 
acid is relatively moderate, being chiefly obtained as an 
accessory product in other industries, such as the manu¬ 
facture of coal gas and that of coke. But it is not only 
for the sake of the gas and the coke that the distillation 
of coal is now carried on ; tar, the mixture of solid and 
liquid products so obtained, has already become an im¬ 
portant article of commerce, supplying the materials for 
an. entire group of industries. Tar yields benzine, the 
primary matter in the manufacture of the aniline colours ; 
anthracene, by the aid of which is produced artificially 
the colouring principle of madder ; and, lastly, a nearly 
inexhaustible quantity of carbolic acid, which, besides 
its hygienic applications, serves as the primary matter 
for the making of a magnificent red colour—coralline. 
We cannot here deal with the coloured derivatives of 
this acid, but its disinfecting properties are well worthy 
the attention of medical men. Its name cannot be pro¬ 
nounced here without recalling the important services 
rendered by it during the late war. If the frightful 
calamities which, under the form of epidemics of every 
kind, ordinarily succeed to the horrors of the fight, dur¬ 
ing this campaign made less victims than in preceding 
wars, doubtless this fortunate result is due to various 
causes; but impartial observers agree that among these 
causes must be reckoned the use of disinfectants, and 
chiefly carbolic acid. 
In order that by the side of products so important, 
those possessing less striking properties may not be for¬ 
gotten, I will here say a few words concerning collo¬ 
dion. The methods of investigation of a science are 
necessarily modified by the object pursued at a certain 
period. While chemists were devoted to the study of 
products of decomposition of organic bodies, nitric acid 
with its oxidizing properties was naturally one of their 
favourite agents. But nitric acid not only acts as an 
oxidizer, in many cases its nitrogen enters into the mole¬ 
cule of the products of decomposition, and bodies were 
so produced that were termed nitrated compounds. Then 
commenced an epoch which might be called the period 
of the treatment by nitric acid; chemists treated by 
this reagent everything that fell into their hands, 
obtaining thus a number of combinations, for some of 
which an application was quickly found. In so treating 
benzine, Mitscherlich obtained nitrobenzine, the first 
and also the most important of the nitrated compounds, 
which, for a long time, has, under the name of essence 
of mirbane, supplied a want of the perfumers, and more 
lately has formed the groundwork of the aniline colours 
industry. By the action of nitric acid upon phenol, Lau¬ 
rent obtained the yellow colouring matter known as picric 
acid. Again, by the aid of nitric acid, Pelou3e obtained 
nitrated starch, or xyloidin, the explosive properties of 
which are utilized in pyrotechny. Schonbein in his turn 
treated cotton in the same manner, and discovered pyro¬ 
xylin, or gun-cotton, for a long time a rival to gun¬ 
powder. But this powerful agent of destruction has also- 
a more peaceful application ; dissolved in ether, under the 
form of collodion, it becomes at the same time the indis¬ 
pensable auxiliary of the photographer, and the faithful 
aid of the surgeon ; instead of causing wounds it heals 
them. 
In analogous circumstances, but in another department 
of organic chemistry, was produced a substance more 
important still to surgery, and therefore to medicine in 
general. As an agent of decomposition, chlorine is no> 
less energetic than nitric acid, and the time came when 
chlorine in its turn secured the preference of chemists. 
In the important researches upon the nature of alcohol 
during the last thirty years, chlorine has played a moot 
important part. Under the action of this element, with 
its affinity for hydrogen, Liebig saw alcohol transformed 
into a series of remarkable products, differing from each 
other in the proportion of chlorine which they contained. 
Among these substances there was one that had escaped 
the researches of Soubeiran, and which Liebig first sub¬ 
mitted to analysis. This was the body now known as 
chloroform. Among the same products of the chlorination 
of alcohol, the great chemist also met another substance, 
the name of which has for some years been in every 
