262 Mr Bischof on the Subterranean Course of Water, S^c. 



In order to ascertain the influence which the junction of a gas 

 with a hydrostatic course would have, I united two glass tubes, 

 four feet in length, with a brass tube, so that they formed an 

 inverted syphon. With the brass tube there was, forming a 

 right angle with it, a second tube with a cock, having a narrow 

 opening for the key. Into this side tube there was a small tu- 

 bular retort cemented. When the cock was closed, the apparatus 

 formed an unbroken water conduit. Even when it was not closed, 

 the water ran uninterruptedly up out of the shorter limb so long 

 as it was poured into the larger one, for the air inclosed in the re- 

 tort was merely somewhat compressed, without being able to enter 

 or come out, owing to the narrow opening of the key of the cock. 

 When carbonic acid gas was evolved, and the cock w^as opened, 

 the gas entered the water course in separate bubbles, rose in the 

 shorter limb, and separated itself from the water of a small basin 

 placed there. During the disengagement of carbonic acid in this 

 true representation of a mineral spring, the water flowed unin- 

 terruptedly from the basin, and the column of water varied little 

 in the larger limb. Since then, under these circumstances, where 

 each gas bubble that enters the water-course entirely fills the 

 tubes, and when it escapes, must produce a momentary inter- 

 ruption of the running of the water, yet there is no perceptible 

 disturbance of the flowing off; this can happen to a still smaller 

 extent in nature, as there the bubbles of gas rarely fill the canals 

 of water. Finally, as the junction of the carbonic acid gas with 

 the water course takes place beneath under a high hydrostatic 

 pressure, the gas is therefore immediately absorbed, can thus 

 produce a smaller disturbing effect on itself, and gradually again 

 makes its appearance when the pressure of the water at the 

 higher points of the course is diminished. 



In order, then, to explain the absorption of the carbonic acid gas 

 by the water, and the subsequent decomposition of the component 

 parts of this carbonic acid-water, — to explain, in one word, the for- 

 mation of a mineral spring rich in carbonic acid, we have only 

 to assume, that, in the interior of the earth, narrow canals coming 

 from beneath join larger ones, that they bring carbonic acid gas, 

 and that the larger canals are filled with water.* 



• From Poggendorff's Annalen der Physik und Chemie, second series, vol. 

 xxxii. no. 16. 



