Wonders of nature science : an every day book for the student and intellectual observer.

Date:
[1873?]
Catalogue details

Licence: Public Domain Mark

Credit: Wonders of nature science : an every day book for the student and intellectual observer. Source: Wellcome Collection.

    584/596 (page 552)
    PROGRESS OF INVENTION. obtained in the following manner: A tube or pipe is introduced into the upcast shaft of the mine, or into the shaft, or portion of the shaft which is used as an outlet for the air, and for the gases gene- rated or evolved in the mine. The tube, or pipe, is carried nearly to the bottom of the shaft, the upper part being carried to some height above the level of the pit's mouth. Into the upper part of the tube, or pipe ordinary, super-heated steam derived from any suitable source is introduced, and thereby a vacuum, or partial vacuum pro- duced, to supply which the air contained in the workings of the mine is necessarily set in motion, and flows in a continual current from all parts of the mine towards the vacuum, or partial vacuum, and carrying with it the noxious gases or vapours which have been generated or evolved, such current being continued as long as the steam is supplied to the ventilating tube. Several tubes may be employed. The advantages of the process are said by the inventor, Mr. Horsfal], to be cheapness and completeness. Producing Oxygen Gas.—Dr. Kirkpatrick, of Brussels, has patented the following method of obtaining oxygen in quantities, and at a small cost : Any hydrated oxide, or any hydrated salt, or other hydrated compound of cobalt or nickel, or any mixture of these substances in a comparatively small proportion, is used with a larger quantity of any soluble hypochlorite, such as hypochlorite of lime or potash. This compound of cobalt or nickel coming into contact with the hypochlorites, decomposes them ; a black precipitate is formed, and this acts on the hypochlorite, setting free oxygen from it. The oxygen gas thus set free escapes with effervescence, and may be collected, in the same manner as hydrogen or carbonic acid, in a gas receiver. The inventor prefers to use hypochlorite of lime, the substance known as chloride of lime, or bleaching powder. When a solution of this salt is used, it should be in a concentrated form, so as to reduce the bulk of the liquid. When it is used in the state of bleaching powder, it should be made into a milk by mixing it with a certain quantity of water. Cobalt salts are said to act better than those of nickel, they being more prompt and quick in causing the decomposition. The nitrate or chloride are the best. The cobalt salt should not be acid, otherwise chlorine will be evolved. When the evolution of oxygen has ceased, the cobalt falls to the bottom as cobaltic oxide. The supernatant liquid may then be drawn off, and a fresh quantity of liquid chloride of lime may be poured in, and this process may be continued till the oxide has lost its efficiency. The same quantity of oxide will often decompose successive additions of chloride of lime almost indefinitely, but when