KARL WILHELM SCHEELE 125 



appearance, and find that it has not the properties mentioned, even 

 when only one of them is wanting, I feel convinced that it is not 

 ordinary air. 



8. Air must be composed of elastic fluids of two kinds. 



First Experiment. — I dissolved one ounce of alkaline liver of sul- 

 phur in eight ounces of water ; I poured four ounces of this solution 

 into an empty bottle capable of holding 24 ounces of water, and closed 

 it most securely with a cork; I then inverted the bottle and placed 

 the neck in a small vessel with water ; in this position I allowed it to 

 stand for fourteen days. During this time the solution had lost a 

 part of its red colour and had also deposited some sulphur : after- 

 wards I took the bottle and held it in the same position in a larger 

 vessel with water, so that the mouth was under and the bottom above 

 the water-level, and withdrew the cork under the water ; immediately 

 water rose with violence into the bottle. I closed the bottle again, 

 removed it from the water, and weighed the fluid which it contained. 

 There were 10 ounces. After substracting from this the four ounces 

 of solution of sulphur there remain six ounces, consequently it is 

 apparent from this experiment that of 20 parts of air six parts have 

 been lost in 14 days. 



9. Second Experiment. — (a) I repeated the preceding experiment 

 with the same quantity of liver of sulphur, but with this difference 

 that I only allowed the bottle to stand a week tightly closed. I then 

 found that of 20 parts of air only 4 had been lost, (b) On another 

 occasion I allowed the very same bottle to stand four months ; the 

 solution still possessed a somewhat dark yellow colour. But no more 

 air had been lost than in the first experiment, that is to say six parts. 



10. Third Experiment. — I mixed two ounces of caustic ley, which 

 was prepared from alkali of tartar and unslaked lime and did not pre- 

 cipitate lime-water, with half an ounce of the preceding solution of 

 sulphur, which likewise did not precipitate lime-water. This mixture 

 had a yellow colour. I poured it into the same bottle, and after this 

 had stood fourteen days, well closed, I found the mixture entirely 

 without colour and also without precipitate. I was enabled to con- 

 clude that the air in this bottle had likewise diminished, from the 

 fact that air rushed into the bottle with a hissing sound after I had 

 made a small hole in the cork. 



11. Fourth Experiment. — (a) I took four ounces of a solution of 



