Vegetable Kingdom on the Animal Creation . 475 
fize, which never happens with leaves of a vine or lime-tree *; 
whereas the green {talks of this plant (the tropseolum majusj 
are at the lame time all covered with ieparate air bubbles ? 
More of thefe remarkable appearances in different plants are to 
be feen in the third feftion of my book on Vegetables. 
If the dephlogifticated air, obtained by means of vegetables 
in water, was air depofited from the water, and purified ot its 
phlogifton, by remaining, during a certain time, in contact 
with the vegetable, it would follow, that this air would be 
fo much the purer the longer it remains in contadt with the 
vegetable ; but it is quite the reverfe. The air obtained from 
the leaves of a vine, to which the air bubbles flick a long- 
while before they detach themfelves and rife up, is never by 
far fo much dephlogifticated as is the air obtained from fome 
American plants, out of which the air ruffles almoft all in 
continual ftreams, as fo many fprings, not remaining a fmgle 
moment upon the leaves. The difference of both airs is lo 
great, that I never got dephlogifticated air from leaves ot 
a vine, lime-tree, and fucli like, whofe goodneis furpafl'ed 
260° (it is commonly a little above 200°) ; whereas I got com- 
monly, from the above mentioned American plants, an an 
whofe goodnefs was of above 3 00 > fometimes even of above 
250°, in a very fair day, this air being put to the teft, according 
to the manner which I have defcribed before t* 
If 
* I have explained the reafon of this Angularity in that plant, in my book, 
where it is mentioned by the name of najlurtium imlicurfi* 
The fempervivum tcBorum, which grows almoft every where upon the roofs 
of houfes, gives alio a very great quantity of dephlogifticated air of an eminent 
quality. It fliould feem, that all fleihy plants particularly excel in the quality 
of yielding fine dephlogifticated air, and a great quantity of it. The agave Ame - 
