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organic products, “ per syntlieticam artem generatum.” As a starting- 
point, he takes a lump of charcoal and hydrogen gas, and actually forces 
these two bodies to unite and form the gaseous hydro-carbon, acetylene. 
This being obtained, he introduces the other elements by appropriate 
methods of treatment, until he arrives at substances of very complicated 
formulas. These researches into the synthetical formation of organic 
bodies may, to the superficial observer, seem devoid of value ; but it must 
be remembered, that by these researches, which M. Berthelot has for many 
years been carrying on, chemists are unfolding the laws by which Nature 
works in her vast laboratories of the animal and vegetable world ; and 
when we remember the vast importance which would attach to the arti- 
ficial production of such bodies as quinine and morphia, the most 
utilitarian will scarcely ask what is the use of these fascinating 
researches. 
II. APPLIED CHEMIST Y. 
Schroeder has examined the effect of filtering air through cotton-wool in 
its relation to fermentation and putrefaction. The conclusion at which he 
has arrived is, that air in its ordinary condition contains germs which are 
removed by passing it through cotton-wool. Organic substances capable 
of putrefaction or fermentation likewise contain similar germs, which are, 
however, entirely destroyed by a more or less prolonged ebullition. If, 
after these have been thus killed, only filtered air is allowed to have access, 
no decomposition will take place, however long it be kept ; but if some of 
these putrefaction-inducing germs are allowed to have access to the body, 
either by the ebullition not being sufficiently prolonged, or the air not 
being effectually filtered, decomposition will be sure to take place. The 
frequent failures in several domestic and culinary operations are thus 
easily explained. In making preserves or bottling fruit, for instance, the 
object is to destroy all the seeds of decomposition present in the fruit, and 
then to cover the jars tightly over with bladder or paper, so that none but 
filtered air can have access to it. The object of the preliminary boiling 
is, therefore, not so much to strengthen the preserve as to kill these germs ; 
and the object of the covering with paper or bladder is not to keep the air 
from it, but to prevent the atmospheric seeds of decomposition from gain- 
ing access. 
The process of galvanizing iron pipes and surfaces — that is, giving the 
metal a coating of zinc — is so commonly used under the impression that the 
zinc, by its polarizing action from contact, will preserve the iron from cor- 
rosion ; and, as the oxide of zinc formed under such circumstances adheres to 
the metal and incrusts it with a body not soluble in water, it has been assumed 
that water passing through such pipes would not become contaminated by 
either iron or zinc. Dr. Hayes has recently found that this idea is incorrect. 
W ater containing some very common organic impurities has been proved to 
have a decided solvent action upon both the iron and zinc ; galvanized 
iron pipes exposed to this water not only dissolving in it, but the usually 
observed protecting power of the zinc was lost — the quantity of salts of 
both metals in solution being frequently so large as to render the water 
unfit for domestic use. It is a generally-received opinion that zinc com- 
pounds, when taken into the system, are not actively poisonous, if even 
