KARL WILHELM SCHEELE 127 



caustic ley. After the precipitate had settled, I poured away the clear 

 fluid and put the dark green precipitate of iron so obtained, together 

 with the remaining water, into the before-mentioned bottle (§8), and 

 closed it tightly. After 14 days (during which time I shook the bot- 

 tle frequently) this green calx of iron had acquired the colour of cro- 

 cus of iron, and of 40 parts of air 12 had been lost, (b.) When iron 

 filings are moistened with some water and preserved for a few weeks 

 in a well closed bottle, a portion of the air is Hkewise lost, (c.) The 

 solution of iron in vinegar has the same effect upon air. In this case 

 the vinegar permits the dissolved iron to fall out in the form of a yel- 

 low crocus, and becomes completely deprived of this metal, (d.) 

 The solution of copper prepared in closed vessels with spirit of salt 

 likewise diminishes air. In none of the foregoing kinds of air can 

 either a candle burn or the smallest spark glow. 



16. It is seen from these experiments that phlogiston, the simple 

 inflammable principle, is present in each of them. It is known that the 

 air strongly attracts to itself the inflammable part of substances and 

 deprives them of it : not only this may be seen from the experiments 

 cited, but it is at the same time evident that on the transference of the 

 inflammable substance to the air a considerable part of the air is lost. 

 But that inflammable substance alone is the cause of this action, is 

 plain from this, that, according to the tenth paragraph, not the least 

 trace of sulphur remains over, since, according to my experiments this 

 colourless ley contains only some vitriolated tartar. The eleventh par- 

 agraph likewise shows this. But since sulphur alone, and also the 

 volatile spirit of sulphur, have no effect upon the air (§ 11. c), it is 

 clear that the decomposition of liver of sulphur takes place accord- 

 ing to the laws of double affinity — that is to say, that the alkalies and 

 lime attract the vitriolic acid, and the air attracts the phlogiston. 



It may also be seen from the above experiments, that a given quan- 

 tity of air can only unite with, and at the same time saturate, a certain 

 quantity of the inflammable substance : this is evident from the ninth 

 paragraph, letter b. But whether the phlogiston which was lost by 

 the substances was still present in the air left behind in the bottle, or 

 whether the air which was lost had united and fixed itself with the 

 materials such as liver of sulphur, oils, &c., are questions of im- 

 portance. 



From the first view, it would necessarily follow that the inflam- 



