320 PHILOSOPHICAL TRANSACTIONS. [ANNO 1782. 



placed this apparatus near the fire till the water in the hottle began to boil; after 

 which he cooled the whole, and found a good quantity of air collected in the 

 bottle, which proved to be dephlogisticated. When he drew the vegetable 

 out of the glass vessel the water sparkled almost like Seltzer water, or like water 

 impregnated by art with fixed air. The vegetable which was still kept in the 2d 

 bottle of exper. ], continued to yield air in the sun-shine, till it ceased to throw 

 up any more air, towards the 7th or 8th day of its being shut up in the vessels. 

 When, after this time, this globular vessel was shook, the water became full of 

 small air bubbles, which for the most part rose to the inverted bottom of the 

 vessel, great part settling on the vegetable, which appeared all covered with 

 them. This sparkling air, which became visible by shaking the glass, could 

 not but be air originally produced by the conferva, and so loosely joined with the 

 water, that it disengaged itself in a great measure from it by the motion of the 

 vessel. After the 10th day the vegetable began to appear withered, yellow, and 

 began to die. Dr. I. found about 8 cubic inches of dephlogisticated air col- 

 lected in the vessel. This proved to be of a very eminent quality, its goodness 

 being of 352°; that is to say, from a mixture of 1 measure of this air, and as 

 many measures of nitrous air as were necessary to complete the full saturation, 

 there were destroyed 3 measures and -,^5- of a measure, the test being made 

 with Abbe Fontana's eudiometer, employed in the manner described in Dr. I.'s 

 book on Vegetables, p. 278 et seq. The quality of this air was superior to that 

 of any air he ever got from this plant in fresh pump water, its goodness proving, 

 in general, to be from 260 to 330°, in the hot-house. This was during the 

 winter, for he never had been able to obtain such fine air from this vegetable in 

 the summer; the reason of which he intended to explain elsewhere. 



Result of exper. 2. — No air at all was produced in the vessel containing the 

 pieces of cloth, during 3 weeks exposure to the sun-shine. For, boiled water, 

 having lost its air, could yield none, at least till after a long time, when some 

 degree of corruption should take place in the animal substance, viz. the pieces 

 of cloth. 



Result of exper. 3. — Not a particle of air appeared in this vessel, though it 

 stood about 2 months on the same place. For, boiled water having no air, the 

 sun could extricate none from it. 



Result of exper. 4. — The conferva began to yield air bubbles the very same 

 day, a little while after its exposure to the sun. The next day it threw up an 

 immense quantity of them. The 5th day it began to throw up less, and ceased 

 entirely about the 7th day, when the quantity of about 14 cubic inches of de- 

 phlogisticated air, of an excellent quality, though less fine than I hat obtained 

 in exper. 1, was collected. The water sparkled, like Seltzer water, by the 

 vessel being shook. This water being exposed to the tire, in an inverted vessel, 



