SCIENTIFIC SUMMARY. 271 
the production of light ; the soda will he very valuable in soap-making, 
and for many other purposes to which this substance is applied. 
A new method of preparing iodine from seaweeds has been suggested 
by Mr. M‘Ardle ; it consists in fermenting the plants in water until the 
organic matter is destroyed, when the inorganic salts will be left behind ; 
a considerable saving is effected by this process, for in the old method 
of burning the seaweeds some of the iodides are volatilized and lost. 
The American oil-wells still continue to furnish large quantities of 
petroleum, which has become an important article of commerce. It 
has been proposed to employ it in the manufacture of illuminating gas. 
Experiments have been made for the purpose of ascertaining the amount 
of gas furnished by the destructive distillation, the oil being allowed to fall 
into a heated retort, together with a little water. The result was satisfac- 
tory. A great advantage in the gas prepared in this manner over coal-gas 
would be, that it would be free from sulphur compounds, and would not 
require so much purification. 
Although a great many processes for rendering textile fabrics fire-proof 
have been proposed, a really good method for accomplishing this end is 
still a desideratum : it is rather difficult to find a substance that answers the 
purpose completely, is cheap, and does not injure the fabric in any manner. 
It is not necessary to render the material altogether incombustible ; but 
only that it should be difficult to inflame, and that, when removed from 
the fire, it should either cease to 'burn, or at least should only smoulder. 
When it is remembered that ladies lose their lives at the rate of 750 per 
annum for the sake of their skirts, the importance of the subject will readily 
be admitted. 
Until quite recently, methylated spirit was supposed to be undrinkable ; 
a careful investigation having been made by eminent chemists for the 
purpose of ascertaining whether or not it could be rendered potable by 
chemical processes, the answer seemed to be decidedly in the negative, at 
least with respect to any wholesale purification of the article. This has, 
however, been accomplished by Mr. Eschwage. He simply passes the 
liquid through a succession of charcoal filters, which remove the unpleasant 
smell and taste. The only part of the process which is claimed in the 
patent is the management of the filters, which are so arranged, that when 
the first becomes exhausted it is removed and replaced by the next in 
order, and the new filter made the last in the series, so that each filter is 
worked until it is completely exhausted. The peculiar flavour of the 
methylic spirit is almost perfectly removed by this treatment, so that it 
could be employed without detriment for medicines, &c. Some druggists, 
however, seem to have no scruples in employing the impure and disagree- 
able liquid in the manufacture of medicinal tinctures. The consequences 
of this are most unpleasant, both to the patient who has the misfortune 
to take the medicine, and to the physician who prescribes it. Draughts, 
intended to stop sickness, and quiet the stomach, have quite the opposite 
effect, and dangerous results ensue. 
So little of the unpleasant taste and odour of the methylic spirit remains 
after the charcoal treatment, that the addition of any flavouring material 
completely conceals it ; and as the apparatus, once fitted up, involves no 
