Illustrations of a novel and successful treatment of psoriasis / by James Adams.

  • James Maxwell Adams
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: Illustrations of a novel and successful treatment of psoriasis / by James Adams. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    up the chimney, leaving only a fourth to be utilized as radiant heat. When coal gas is used as fuel, and the ordinary jet for lighting purposes employed, the convected heat generated amounts to 84 per cent., or five-sixths of the whole, and only 16 per cent,, or about one-sixth, is given out as radiant heat. When the Bun- sen burner, in any of its forms, is employed, the heat generated is nearly altogether that of convection, about 6 per cent, only con- sisting of radiant heat. The difference in the proportion of radiant and of convected heat, emitted by the same gas by a mere change in the method of combustion, depends on the presence of solid cai'bonaceous particles in the luminous flame. This question has been thoroughly worked out by Tyndall, and the results are recorded in his Contributions to Molecular Physics in the domains of Radiant Heat. Using an apparatus of sensitive precision, he found the radiation from the luminous gas flame was fully two-and-a-half times that from the non-luminous flame. The degree of force—not the degrees of temperature—in the luminous flame was 30, and the radiation fell to a force of only 12 the instant the flame became non-luminous. But, by introducing solid matter, the radiation originating in the non-luminous flame ' became so intense that a spiral of platinum plunged in the flame brought up the index to a force equal to 200—that is, there was instantly generated an amount of radiant heat more than 6 times that from the luminous gas flame, and more than 30 times that of the non-luminous flame. It is mainly, says Tyndall, by con- vection that the hydrogen flame dispenses its heat; though its temperature is higher, its sparsely-scattered molecules are not able to cope in radiant energy with the solid carbon of the luminous flame. The same is true for the flame of the Bunsen burner. The moment the air (which destroys the solid carbon particles) mingles with the gas flame, the radiation falls considerably. Conversely, a gush of radiant heat accompanies the shutting out of the air, which deprives the gas flame of its luminosity. When, therefore, we introduce a platinum wire into a hydrogen flame, or carbon particles [or platinum, or various other solids] into a Bunsen flame, we obtain not only waves of a new period, but also convert a large portion of the heat of convection into the heat of radiation. To obtain in a practical form the means of converting the heat of convection into the heat of radiation has been the chief aim of my .efforts for the improvement of gas stoves; and I will now give a