very quick; that of M. Gay-Lussac, which is 62 in the
minute on ordinary occasions, now gave 80; and mine, which is ordinarily
89, gave 111. This acceleration was felt by both of us in nearly the
same proportion. Nevertheless, our respiration was in no way interfered
with, we experienced no illness, and our situation seemed to us
extremely agreeable."

The following is their report to the Galvanic Society--

"We have known for a long time that no animal can with safety pass into
an atmosphere much more dense or much more rare than that to which it
has been accustomed. In the first case it suffers from the outer air,
which presses upon it severely; in the second case there are liquids or
fluids in the animal's body which, being less pressed against than
they should be, become dilated, and press against their coverings or
channels. In both cases the symptoms are nearly the same--pain, general
illness, buzzing in the ears, and even haemorrhage. The experience of
the diving-bell has long made us familiar with what aeronauts suffer.
Our colleague (Robertson), and his companion, have experienced these
effects in great intensity. They had swelled lips, their eyes bled,
their veins were dilated, and, what is very remarkable, they both
preserved a brown or red tinge which astonished those that had seen them
before they made the ascent. This distension of the blood-vessels would
necessarily produce an inconvenience and a difficulty in the muscular
action."

Chapter II. Ascent of M. Gay-Lussac Alone--Excursions of MM. Barral and
Bixio.

Respecting this ascent, Arago states that M. Gay-Lussac has reduced to
their proper value the narratives of the physical pains which aeronauts
say they suffer in lofty aerial ascents.

M. Gay-Lussac says:--"Having arrived at the most elevated point of
my ascent, 21,000 feet above sea level, my respiration was rendered
sensibly difficult, but I was far from experiencing any illness of a
kind to make me descend. My pulse and my breathing were very quick;
breathing very frequently in an extremely dry atmosphere, I should not
have been surprised if my throat had been so dry as to make it painful
to swallow bread."

After having finished his observations, which referred chiefly to the
magnetic needle, with all the tranquillity of a doctor in his study,
Gay-Lussac descended to the earth between Rouen and Dieppe, eighty
leagues from Paris.

After the names of Robertson, Gay-Lussac, and Biot,