Researches on magnetism, electricity, heat, light, crystallization, and chemical attraction : in their relations to the vital force / By Karl, Baron von Reichenbach. Tr. and ed. at the express desire of the author, with a preface, notes, and appendix, by William Gregory. With three plates and twenty-three wood-cuts. Parts I and II, including the second edition of the first part, cor. and improved.

  • Reichenbach, Karl, Freiherr von, 1788-1869.
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: Researches on magnetism, electricity, heat, light, crystallization, and chemical attraction : in their relations to the vital force / By Karl, Baron von Reichenbach. Tr. and ed. at the express desire of the author, with a preface, notes, and appendix, by William Gregory. With three plates and twenty-three wood-cuts. Parts I and II, including the second edition of the first part, cor. and improved. Source: Wellcome Collection.

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    phorescence, and according to these, it was out of the question to bring into a dark room an objeet which had been exposed to the rays of the sun. Indeed, HEINRICH has shown, that in these circumstances a large proportion of all solid bodies gives out light, visible even to the ordinary eye. The arrange- ment which I adopted, in order to make experiments, during sunshine, in perfect darkness, was the following. From my study, a private stair leads to the lower story, where my col- lections and instruments are kept. I shut up completely the window which lighted the stair, and when both doors were closed, the stair was rendered perfectly dark. It was easy to communicate with any one shut up in this dark receiver, so to speak ; and to hear and understand what was spoken aloud, either on the stair or in either of the two rooms connected with it, above and below. Mlle. REICHEL was so obliging as to allow herself to be shut up in this dark stair; and I mention these details particularly, because a great number of experiments on luminous phenomena, all to be given in their proper place, were conducted here. In describing these, I shall have to refer to the locality now mentioned. This arrangement also supplied the best test of the accuracy of the sensitive observer; who, when in her prison, at a considerable distance either above or below the room in which I was at work, could never know what alterations were there made in the experiments, but could only observe and describe the effects, when and in whatever form she perceived any to be manifested. In my room above, I had, ready prepared, several plates of about 800 square inches, of copper, iron, and zinc; of gilt metals; large pieces of lead foil, and steeped in melted sulphur, and other substances. I attached these successively to an iron wire, 33 feet long and 0.0794 of an inch thick. I then carried the wire through the key-hole of the upper door, (in which only a sufficient aperture to admit the wire had been left,) down the stair to the patient, and caused her to take the wire in her hand, and to point the end of it upwards. After she had re- mained so long in this position that her eyes had been brought into the state best adapted for seeing in the dark, I moved the plate at the other end into the sunshine, and did this suc-