370 Foreign Literature and Science: 



sure being measured by a gague belonging to the pump 

 When the water from the injecting pump first begins to 

 press out the pipe, little or no alteration is observed on it for 

 some time. As the operation proceeds, however, the pipe 

 gradually swells throughout its whole length, until at last a 

 small protuberance is observed rising in some weak part, 

 which increases until the substance of the pipe, becoming 

 thinner and thinner, is at last rent asunder, when the pipe 

 breaks with a crash, and the water issues with great vio- 

 lence. 



In the first experiment, the pipe was of one and a half 

 inch bore, and the metal, which was remarkably soft and 

 ductile, one fifth of an inch in thickness. This sustained a 

 power equivalent to that of a column of water one thousand 

 feet high, equal to thirty atmospheres, or four hundred and 

 twenty pounds per square inch of internal surface, without 

 alteration ; but with a pressure of water equal to twelve 

 hundred feet of water it began to swell, and with fourteen 

 hundred feet, or six hundred pounds on the square inch, it 

 burst. When measured after the experiment, it was found 

 to have swelled until it became of a diameter of one and 

 three fourths of an inch. The edges of the fracture were 

 not ragged, but smooth and sharp like a knife. 



In a second experiment, the pipe was two inches in diam- 

 eter, and one fifth of an inch in thickness. It sustained a 

 pressure equal to that of a column of water eight hundred 

 feet in height with hardly any swelling, but with one thou- 

 sand feet it burst. The fracture here Was not so fine as in 

 the former pipe, the metal being much less ductile. — Cale- 

 donian Mercury. 



3. Inspiration of Inflammable Gas. — By Signor Giacomo 

 Cardone. — This experiment was made in consequence of 

 the difference of opinion on the effects of this gas on the 

 lungs, entertained by Scheele, Fontana, and others. The 

 air being expelled from the lungs as much as possible, the 

 mouth-piece of a bladder containing thirty cubic inches of 

 the gas was applied to the mouth, and the gas inhaled at two 

 inspirations. An oppressive difficulty of respiration, and a dis- 

 tressing constriction at the mouth of the stomach were the 

 first sensations ; these were followed by abundant perspira- 

 tion, a general tremor over the whole body, seeming to com- 

 mence at the knees ; an extraordinary sense of heat, slight 



