126 CLASSICS OF MODERN SCIENCE 

 sulphur in lime-water; I poured this solution into a bottle and closed 

 it tightly. After 14 days the yellow colour had disappeared, and of 20 

 parts of air 4 parts had been lost. The solution contained no sul- 

 phur, but had allowed a precipitate to fall which was chiefly gypsum, 

 (b.) Volatile liver of sulphur likewise diminishes the bulk of air. (c) 

 Sulphur, however, and volatile spirit of sulphur, undergo no alteration 

 in it. 



12. Fifth Experiment. — I hung up over burning sulphur, linen rags 

 which were dipped in a solution of alkali of tartar. After the alkali 

 was saturated with the volatile acid, I placed the rags in a flask, and 

 closed the mouth most carefully with a wet bladder. After three 

 weeks had elapsed I found the bladder strongly pressed down; I in- 

 verted the flask, held its mouth in water and made a hole in the blad- 

 der ; thereupon water rose with violence into the flask and filled the 

 fourth part. 



13. Sixth Experiment. — I collected in the bladder the nitrous acid 

 which arises on the dissolution of the metals in nitrous acid, and after 

 I had tied the bladder tightly I laid it in a flask and secured the mouth 

 very carefully with a wet bladder. The nitrous air gradually lost its 

 elasticity, the bladder collapsed, and became yellow as if corroded by 

 aqua fort is. After 14 days I made a hole in the bladder tied over the 

 flask, having previously held it, inverted, under water ; the water rose 

 rapidly into the flask, and it remained only two-thirds empty. 



14. Seventh Experiment. — (a.) I immersed the mouth of a flask 

 in a vessel with oil of turpentine. The oil rose in the flask a few lines 

 every day. After the lapse of 14 days the fourth part of the flask 

 was filled with it. I allowed it to stand for three weeks longer, but 

 the oil did not rise higher. All those oils which dry in the air, and 

 become converted into resinous substances, possess this property. 

 Oil of turpentine, however, and linseed oil rise up sooner if the flask 

 is previously rinsed out with a concentrated sharp ley. (b.) I 

 poured two ounces of colourless and transparent animal oil of Dippel 

 into a bottle and closed it very tightly ; after the expiration of two 

 months the oil was thick and black. I then held the bottle, inverted, 

 under water and drew out the cork; the bottle immediately became 

 one-fourth filled with water. 



15. Eighth Experiment. — (a.) I dissolved two ounces of vitriol of 

 iron in thirty-two ounces of water, and precipitated this solution with a 



