NUTRITIOJI OP VEGETABLES. 23 



into which I had put with great caution some lime, that was 

 slaked, and suitably moistened with water. It was not long 

 before the red colour of the paper was changed to blue. 

 This effect was not unknown to Fourcroy. 



2. Into a retort I put with all possible precaution a certain ^^^^^^ ^ 

 quantity of lime and water, and by distillation I obtained a 

 liquor impregnated with an intolerable smell of lime. This 

 liquor left a disagreeable impression on the palate, and had 

 manifestly alkaline properties. 



Alcohol by its volatility carries up in vapour a much larger Still more rises 

 quantity of lime, as appears from an experiment of Proust. "^^^^ ^P'"^- 

 In order to obtain spirit free from acetic acid, he distilled 

 25lbs. of red wine with a handful of quicklime. The pro- 

 <luct was so much impregnated with the taste and smell of 

 the lime, that he was surprised. When redistilled it had 

 the same taste, precipitated metallic solutions and oxalic 

 acid, and restored tlie blue of litmus. 



Lime is not the only fixed alkali, that shows a disposition Other fixed al- 

 to rise at a pretty low temperature. kalis^nse at a 

 A solution of potash, subjected to distillation, afforded me p^^ ^^^ ,j ^j^^ 

 a water with a strong lixivial smell. This water redistilled led. 

 retained the same smell, and gave with nitrate of lead a 

 white flocculent precipitate, which was completely soluble in 

 distilled vinegar. 



But there are other substances beside alkalis, the volatility Other snbstan- 

 of which is so little apparent in the temperature of the at- ^^j partially 

 mosphere, that it is discoverable only from its effects on 

 organized beings. 



Some Dutch chemists set plants in water, by the side of Quicksilver. 

 which they placed, a small bottle of mercury, and covered 

 the whole with a jar standing in water. On the third day 

 the plants were covered with black spots, and on the fourth, 

 the fifth, or at latest the sixth, they were entirely black. 

 The effects were the same when the jar rested on pieces of 

 cork on a table. Other plants lived a long time under simi- 

 lar circumstances except the presence of mercury. 



Sennebier and Hubert too have shown, that the vapour Other vapours 

 of sulphuric ether prevents germination from taking place, i"i""o"sto 

 without altering the quantity of the air. Camphor, oil of 

 turpentine, assafetida, vinegar, ammonia, bodies in a state 



of 



