August 19, 1871.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
155 
taincd by exposing paraffin to a high temperature in 
closed vessels. By this treatment it is almost completely 
•resolved into liquid hydrocarbons, whose boiling-points 
range from 18° C. to 300° C.; those boiling under 100° C. 
have been examined, and consist chiefly of olefines. In 
connection with this subject, it may be interesting to 
recall the experiments of Pelouze and Cahours on the 
Pennsylvanian oils, which proved to be a mixture of 
carbohydrogens belonging to the marsh-gas series. 
An exposition of Berthelot’s method of transforming 
sin organic compound into a hydrocarbon containing a 
maximum of hydrogen, has appeared in a connected 
form. The organic body is heated in a sealed tube, with 
a large excess of a strong solution of hydriodic acid, to 
the temperature of 250°. The pressure in these experi¬ 
ments Berthelot estimated at 100 atmospheres. He has 
thus prepared ethyl hydride (Q,H 6 ) from alcohol, alde- 
etc.; hexyl hydride (C 6 H U ) from benzol. Ber¬ 
thelot has submitted both wood charcoal and coal to the 
reducing action of hydriodic acid, and, among other in¬ 
teresting results, he claims to have obtained in this way 
oil of petroleum. 
By the action of chloride of zinc upon codeia, Mat- 
thiessen and Burnside have obtained apocodeia, which 
'stands to codeia in the same relation as apomorphia to 
•morphia, an atom of water being abstracted in its forma¬ 
tion. Apocodeia is more stable than apomorphia, but 
the action of reagents upon the two bases is very similar. 
As regards their physiological action, the hydrochlorate 
of apocodeia is a mild emetic, while that of apomorphia 
is an emetic of great activity. Other bases have been 
■obtained by Wright by the action of hydrobromic acid 
on codeia. 
We are indebted to Crum-Brown and Fraser for an 
Important work on the relation between chemical con¬ 
stitution and physiological action. It has long been 
•known that the ferrocyanide of potassium does not act 
•as a poison on the animal system, and Bunsen has shown 
that the kakodylic acid, an arsenical compound, is also 
inert. Crum-Brown and Fraser find that the methyl 
•compounds of strychnia, brucia, and thebaia are much 
less active poisons than the alkaloids themselves, and the 
character of their physiological action is also different. 
The hypnotic action of sulphate of methyl-morphium is 
less than that of morphia. But a reverse result occurs 
in the case of atropia, whose methyl and ethyl deriva¬ 
tives are much more poisonous than the salts of atropia 
dtself. 
Before proceeding to the subject of fermentation, I 
nay refer to Apjohn’s chemico-optical method of sepa¬ 
rating cane sugar, inverted sugar, and grape sugar from 
•one another when present in the same solution, by ob¬ 
serving the rotative power of the syrup before and after 
inversion, and combining the indications of the saccharo- 
meter with the results of an analysis of the same syrup 
after inversion. Heisch’s test for sewage in ordinary 
water is also deserving of notice. It consists in adding 
:a few grains of pure sugar to the water, and exposing it 
•freely to light for some hours, when the liquid will be¬ 
come turbid from the formation of a well-marked fungus, 
•if sewage to the smallest amount be present. Frankland 
'has made the important observation that the develop¬ 
ment of this fungus depends upon the presence of a phos¬ 
phate, and that if this condition be secured, the fungus 
will appear even in the purest water. 
The nature of fermentation, and in particular of the 
ralcoholic fermentation, has been lately discussed by 
Liebig with consummate ability, and his elaborate me¬ 
moir will well repay a careful perusal. Dr. Williamson 
has also given a most instructive account of the subject, 
particularly with reference to the researches of Pasteur, 
in his recent Cantor lectures. A brief statement of the 
present position of the question will therefore not be out 
of place here. It is now thirty-four years since Cagniard 
de la Tour and Schwann proved by independent observa¬ 
tions that yeast globules are oi’ganized bodies capable of 
reproduction by gemmation; and also inferred as highly 
probable that the phenomena of fermentation are induced 
by the development or living action of these globules. 
These views, after having ^fallen into abeyance, were 
revived and extended a few years ago by Pasteur, whose 
able researches are familiar to every chemist. Pasteur, 
while acknowledging that he was ignorant of the nature 
of the chemical act, or of the intimate cause of the split¬ 
ting up of sugar in the alcoholic fermentation, main¬ 
tained that all fermentations, properly so called, are cor¬ 
relative with physiological phenomena. According to 
Liebig, the development and multiplication of the yeast- 
plant, or fungus, is dependent upon the presence and 
absorption of nutriment which becomes part of the living 
organism, while in the process of fermentation, an exter¬ 
nal action takes place upon the substance, and causes it 
to split up into products which cannot be made use of by 
the plant. The vital process and the chemical action, 
he asserts, are two phenomena which in the explanation 
must be kept separate from one another. The action of 
a ferment upon a fermentable body he compares to the 
action of heat upon organic molecules, both of which 
cause a movement in the internal arrangement of the 
atoms. The phenomena of fermentation Liebig refers 
now as formerly to a chemico-physical cause, the action, 
namely, which a substance in a state of molecular move¬ 
ment exercises upon another of highly complex consti¬ 
tution, whose elements are held together by a feeble 
affinity, and are, to some extent, in a state of tension or 
strain. Baeyer, who considers that in the alcoholic and 
lactic fermentations one part of the compound is reduced 
and another oxidized, adopts the view of Liebig that the 
molecules of sugar which undergo fermentation do not 
serve for the nourishment of the yeast-plant, but receive 
an impulse from it. All are, however, agreed that fer¬ 
mentation is arrested by the death of the plant, and even 
a tendency to the acetous fermentation in wine may be 
checked, as Pasteur has shown, by heating the wine to. a 
temperature a little below boiling-point in the vessel in 
which it is afterwards to be kept. 
Dr. Andrews concluded by saying that he could not 
refrain from bearing tribute to the great ability and in¬ 
domitable perseverance which characterize the labourers 
in the great field of organic chemistry. It would scarcely 
be possible to conceive any work more intelligently un¬ 
dertaken or more conscientiously performed than theirs, 
yet much of it, from its abstruse character, receiving 
little sympathy or encouragement except from the band 
of devoted men who have made this subject the chict 
pursuit of their lives. They will, however, find their 
reward in the consciousness that they have not lived in 
vain, but have been engaged, and successfully engaged, 
in the noble enterprise of extending for the benefit of 
the human family the boundaries of scientific knowledge. 
Nor is there any real ground for discouragement: I ara- 
day, Graham, Magnus, and Herschel, who have left 
their impress on this age, were all distinguished chemi¬ 
cal as well as physical discoverers; and the relations of 
the sciences are becoming every day so intimate that 
the most special research leads often to results ot wide 
and general interest. 
BRITISH MEDICAL ASSOCIATION. 
The British Medical Association commenced its thirty- 
ninth annual Meeting on Tuesday evening, August 8, 
at the Assembly Rooms, Plymouth. # 1 n 
Dr. Charlton, of Newcastle, took the chair, and, aitei 
the reception of an address of welcome from the May 01 
and Corporation of Plymouth, proceeded to deliver his 
valedictory address. He said that, contrary to the ex¬ 
pectations indulged in when he assumed office at the 
Newcastle meeting, the past year, instead of. being one 
of great excitement among those interested m medical 
legislation, had been singularly barren ot incident 
