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more or less disappeared, and carbonic acid was, in a 
greater or less degree, produced. Sometimes the 
consumption of oxygen was complete, and an equal 
bulk of carbonic acid was produced ; at other times, 
the oxygen gas only partially disappeared, and the 
carbonic acid formed was in a much smaller propor- 
tion. Sometimes the nitrogen was in part consumed, 
at other times it remained unaltered, and in some in- 
stances its quantity was actually increased j yet no 
attempt is made to investigate the causes of this dis- 
cordance, or to discover the sources whence such 
great variations could proceed. Equal credit seems 
to have been attached to the most imperfect and the 
most perfect trials ; and the author appears, by the 
repetition of his experiments, to have simply added 
to their number without proportionally increasing 
their value. Of the labours of his predecessors and 
contemporaries he seems either to have been entirely 
ignorant, or to have maintained an injurious silence ; . 
and hence he is sometimes found to announce well- 
known facts, with all the surprise and importance of 
new discoveries. Lastly, the effects produced in the 
air by living, by dead, and even by putrefying ani- 
mals, are considered by him to proceed from the same 
causes, and to be accomplished in a similar manner ; 
and thus the results of decomposition are uniformly 
confounded with those which succeed to the exercise 
of living action. 
540. From these various sources of inaccuracy, it 
is scarcely possible to deduce, from this author's ex- 
periments, any thing farther, with regard to respira- 
tion, than the general facts, that, in all animals, oxy- 
