I 
37 
Now, 14 cubical inched of air weighs 7 graind, and the red par tided or 
calx of mercury, being carefully collected, weighed 00 graind. The mercury, 
therefore, by being calcined, had acquired an increade of weight of 7 graind, 
the exact weight of air which seemed lodt .* 
The 80 cubical inched of air remaining in the glass after this calcination 
was ended being examined, it was found to possess thede didtmguidhing 
propertied. 
An animal being put into it was duffocated in a few minutes,.. .and when 
* 
a taper was plunged into it, it was extinguidhed, as if it had been immersed 
in water. 
Thid gad , or air , has been called phlogidticated air, non-red [nr able air , 
noxioud or mephitic air , impure cdr\ but the French chemists have preferred 
the term a%otic gad (lethal air) from the Greek words privative ; and 
life, as thid air so quickly destroys life. 
layoisier’s second experiment. 
Having taken 00 graind of the calx of mercury , the product of the ladt 
proceddf Lavoisier put it into a glass retort fitted to a proper apparatus for 
receiving aerial products. 
Having applied a much dtronger heat than in the former experiment, he 
observed that at first, in proportion as the calx of mercury became heated, 
the intensity of its colour augmented; but soon after the calx began gradu¬ 
ally to decrease in bulk, and in a few minutes itd red colour altogether did¬ 
ap pear ed, and the 00 graind of calx of mercury was converted into the 83 
graind of running mercury, and 14 cubical inched of an aerial fluid passed 
over into the recipient. 
Now these 14 cubical inched of air weighed 7 graind , the exact weight 
of the air condumed by the calcination of the mercury in the first experi¬ 
ment;^: and the 83 graind of the calx of mercury reduced § to a metallic 
* The conclusion is obvious; and in the next experiment we shall find, that the 14 cubical inches 
of air, which was absorbed by the mercury, and converted it to a calx, was the vital or respirable 
part of our air. 
f Not from any peculiar property of its own, but because the vital or respirable part was ab¬ 
stracted from it, as will be seen from the next experiment. 
+ Had the too cubical inches of atmospheric air contained a larger share of oxygen or vital air, 
more mercury would have been calcined. For calculation, as this experiment shews, is nothing more 
than the combination of vital air with any metallic body. 
§ From the Latin word reduco, to bring back. Reduction is the bringing back a metal converted, 
into a calx to its pristine state. 
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