The principles of inorganic chemistry / by Wilhelm Ostwald ; tr.with the author's sanction by Alexander Findlay.

Date:
1902
Catalogue details

Licence: In copyright

Credit: The principles of inorganic chemistry / by Wilhelm Ostwald ; tr.with the author's sanction by Alexander Findlay. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    CHAP. colour, its form, its weight, etc. Movement is therefore a physical phenomenon. We can place the piece of sulphur in hot water and it acquires thereby the property of producing the sensation of warmth when placed on the skin. No other change can be perceived. If we rub it with a cloth, it acquires the property of attracting light objects, such as scraps of paper; it has become electrified. Here again, no other change in its properties can be recognised. These phenomena are, therefore, also to be assigned to physics. We now bring the piece of sulphur in contact with a flame. It takes fire and begins to burn with a blue flame. The smell of burn- ing sulphur, also, becomes noticeable, and if the burning lasts some time, the sulphur disappears; it is burnt. In this process, not only do particular properties of the sulphur undergo change, but the sulphur disappears altogether, so that Ave can no longer see it at all. From the smell Avhich arises at the same time, and Avhich was not there before, Ave can conclude that something else has been produced from it. In this case, therefore, the sulphur has undergone a chemical process. We recognise such chemical processes everyAvhere around us. The burning of petroleum and stearin in our lamps and candles, of coal in our fires, the transformation of food-substances in the animal organism, the processes connected AAuth the germination and groAvth of plants, the rusting of iron, the turning sour of milk, the putrefaction of dead animal and vegetable matter and innumerable other phenomena of a like kind, are identified as chemical through the disappearance of exist- ing bodies and the appearance of new ones possessing other proper- ties. To establish the laAvs of all these phenomena is the task of the science of chemistry. Experience.—In describing the simple phenomena Avith which Ave have just been occupied, Ave have employed Ararious conceptions and ideas of Avhich we daily make use and Avhich are therefore familiar to us. For scientific purposes, hoAvever, we dare not rest satisfied with the someAvhat indefinite and arbitrary notions Avhich Ave attach to such words in ordinary life ; their full purport must be examined and their meaning established Avith definiteness. That Avhich enters directly into the consciousness of a particular individual, is the changing conditions of his mind. We soon distin- guish between the inner and the outer experiences; the former are dependent on our Avill, the latter are not, or are so only indirectly. On account of this independence, Ave assume that such experiences have their cause in something that is different from our person, and the totality of these experiences Ave call the outer world. All our experiences form a series of diverse states or processes differing among themselves. An event is never repeated in exactly the same Avay as it had once occurred. Our relation to life Avould, therefore, be that of a wanderer in the
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