38 
state being examined, had lost in weight 7 grains, the exact weight of the 
air now obtained. Tliu air possessed these peculiar properties. 
An animal being placed in it, became remarkably lively , a taper 
burnt in it with a daz%lmg splendour ; and charcoal, instead of consuming 
quietly away, as it does in common air, burnt with a jlame, attended with 
a decrepitating noise, and threw out such a brilliant light that the eyes could 
hardly endure it. 
This species of air was discovered almost at the same time by Dr. 
Priestley, and Mr. Scheele. Dr. Priestley gave it the name of Dephlo- 
gisticated or Pure Air-, Mr. Scheele called it Empyreal Air ; and Lavoisier 
first named it Highly Respirable Air, or Vital Air-, and afterwards, as it 
forms acids, by combining with certain bodies, he adopted the term Oxygen 
Gas (Acid-making Air), from the Greek words vl»s, sour ; and ysue/im, to 
beget*. 
THE SYNTHESIS, 
r\. VITAL AIR, 
Or Reunion of < and 
L. AZOTIC AIR. 
Lavoisier then repeated the same experiments as before related, and 
re-combined the two elastic fluids, which he had separately obtained in the 
two experiments of calcination and reduction , viz. the 84 cubical inches of 
the azotic air, and the 14 cubical inches of the oxygen air, and he pro¬ 
duced from this combination an elastic fluid precisely similar in all its pro¬ 
perties to atmospheric air, contributing in the same way to a repetition of 
the same experiments, and possessing exactly the same power of supporting 
animal life, and combustion. 
* If sulphur or charcoal be burnt in oxygen or vital air, in a close vessel, and the fumes be con¬ 
densed in water, this water will acquire an acid taste, and be increased in weight exactly correspond¬ 
ing to the weights of sulphur or charcoal consumed, and that of the oxygen air destroyed. Sulphur 
united thus with oxygen, the fumes being collected in water, will form vitriolic acid; and charcoal 
combined with oxygen, and diffused in water, will form the carbonic, or aerial acid water. 
The calces of metals the Trench chemists call oxyds, which signifies a body impregnated with a 
certain quantity of oxygen, but not sufficient to render it perceptibly acid. It is from these chiefly 
that we obtain the pure vital air. The oxyd of manganese parts with its oxygen so readily, that if 
pounded and put into an iron retort with but a moderate heat from the furnace, the air will be forced 
from it, and passing along an iron tube, whose termination is in water, will enter into any vessel 
filled and inverted over the pneumatic tub, and afford the pure separate oxygen air, the just pride of 
modern philosophy. Rhis air is most fit for medicinal purposes. If vitriolic acid (sulphur and oxygen) 
be added to the manganese in a glass vessel, the mere heat of an Argand lamp will be sufficient to 
produce speedily enough of pure oxygen air for the performance of chemical experiments. 
