322 Memoirs of the Life of Lewis Brugnatelli. 
the very year in which he graduated (1784), when he discovered, 
that the gastric juice had ‘invariably an acid character m carni- 
vorous animals, while in herbivorous it was uniformly alkaline and 
putrescent. He was led to these experiments by the cireum- 
stance of Professor Carminati being engaged in making physio- 
logical researches on the gastric juice at the same period in the © 
hospital. It was then ascertained that the gastric juice of carni- 
vorous animals had great curative powers when applied to foul 
ulcers or wounds, but that of herbivorous was destitute of this pro- 
perty. Professor Brugnatelli continued his researches ; and com- 
bining the effects of the different kinds of gastric juice with that 
acid which he had also discovered in the stomach of all carni- 
vorous birds, he succeeded in determining their solvent powers in 
the corrosion not only of metals but calcareous stones ; and even 
pieces of rock- crystal and agate introduced into the stomach 
exhibited signs of its consumptive powers. These experiments were . 
followed by an examination of the action of nitric acid on cork, 
in which the Professor discovered that a new and peculiar acid 
was developed, and which has since heen called the suberic acid. 
At the same time he discovered a method of preparing fulminat- 
ing silver, which he improved and extended to other substances ; 
and which is esteemed preferable to the process of Howard, being 
that now generally used for making fulminating balls, &e. ‘The 
consequence of these discoveries led him to make new experi- 
ments on the salts (particularly nitrats) which had the property 
of detonating when mixed with a combustible body, and exposed 
to friction or a blow of a hammer, in order to demonstrate the 
quantity of caloric which might exist in bodies even in the solid 
state. He extended his ideas to the various kinds of combus- _ 
tion, proving the necessity of determining the difference between 
them ; some being cold and obscure, others accompanied with 
the most vivid development of caloric and light,—circumstances 
which must have a very great influence on the properties of a 
body that was united to oxygen. In the case of cold and ob- 
scure combustion, the body continues capable of presenting the 
detonating phenomena of caloric and light when brought in con- 
tact with other combustible bodies; but it loses entirely this 
property if the caloric and light were disengaged previous to its 
union with oxygen. Of these facts and observations Thomson 
availed himself in his System of Chemistry, article Combustion, © 
which is chiefly derived from the luminous researches and in- 
genious observations of the Pavian Professor. On these facts was 
founded the hypothesis respecting the constitution of oxygen, 
modifying the principles of Lavoisier, according to which many 
phenomena of combustion are very plausibly explained. 
Among the ingenious researches and observations of Professor 
Brugnatelli 
