1808.] 
Austria, and having encamped themselves 
in the environs of Madrid, the courtezans 
of the city resolved to signalize their zeal 
for the cause of Philip. Those who were | 
most notoriously afflicted with a certain 
disorder, were accustomed to perfume 
themselves and regularly visit every night 
the camp of the Portuguese; the con- 
sequence was that in less than three 
weeks, more than six thousand of the 
enemy were consigned to the hospitals, 
where the greater number of them died. 
M. de Saintfoix, in his Essats Histo- 
_—— ny 
Proceeding's of Learned Societies. 
49 
riques sur Paris, tom, 8, p. 235, remarks, 
that this curious event was once the sube. 
ject of a debate at which he was present. 
The question to tbe decided was, Whe- 
ther these women, by thus prostituting 
themselves to the Portuguese, were guilty 
of sin; or whether the intention did not 
justify the deed? Those who maintained 
that there was no guilt in the act, argu- 
ed, that as it is permitted to slauyhter the 
enemy, burn his cities, ravage his country, 
and annoy him ‘by every possible mode : ad 
foriori, itis lawfal to give him the 
PROCEEDINGS OF LEARNED SOCIETIES. 
NATIONAL INSTITUTE OF FRANCE. 
REPORT of the TRansacrions of the Ma- 
THEMATICAL CLASS Of the INSTIQUTE, | 
for the lust HALF yEaR of 1806.° By 
M. DELAMBRE, SECRETARY’ to the IN- 
STITUTE, aes RARE ° 
HE class is ‘acquainted. with how 
much success’ M, -Laplace has sub-. 
jected to analysis, the: phenontena of 
capillary tubes; a subject the elucidation 
of which many distinguished=philoso~ 
phers and geomegricians hat fattempted 
in vain. This analysis furnished him 
with an explanation of these ‘singular 
phenomena. It was long ago,remarked, 
that two bodies swimmiv§~on a fluid, 
and in the contrary case recede from, 
each other. 
_ M. Laplace, we are informed, explains. 
in detail the circumstances which give 
birth to all these phenomena, the limits 
which separate them, and the point where 
repulsion changes into an apparent ate 
traction, and combines the whole in twa 
general theorems, or algebraical formula, 
wherein we readily perceive the whole 
of his doctrine, of which all that precedes 
is only the translation into common 
language. 
The memoir concludes with an expe- 
riment, made with much care, by M. 
which rises orsinks aroundthem, approach, Hauy.» A square sheet.of laminated talc 
each other, and unite by an accelerated 
motion; but they are more’ fréquently 
repelled, if the fluid, which rises around 
was suspended by a very locse thread, 
so that its lower part was immersed in 
water. /In this state, when he plunged 
the one, sinks about the other, and™into the. same fluid, and et a little 
in this case, if we suitably diminish the 
distance, attraction may be observéd 
to succeed to repulsion. These sur- 
prising phenomena long™ since attracted 
the attention of philosophers. 
Amontons, a hundred years ago, had . 
endeavoured to'explain them; but M. 
Monge, in the Memoir of the Academy 
of Sciences, for 1787, has demonstrated 
the insufficiency, and even the accuracy 
of the principles of that philosopher. 
This memoir contains many philosophical 
observations and interesting experiments. 
Lastly, M. Laplace has submitted all 
these effects to the same analysis, froin ~ 
which he had deduced the phenomena 
of capillary attraction. He proves that, 
if two parallel planes have their inferior 
parts dipped into a fluid, their internal 
and external surfaces support a pressure, 
of which he gives the analytical ex- 
pression, We may conceive that, if the 
external be superior to the internal 
pressure, the two planes must approach, 
Montury Maa. No. 167. 
s 
distance, the ibferior part of a paral- 
lelopiped of ivory, in a vertical situation, 
and parallel to the square of talc, a sen- 
sible repulsion was imimediately obser- 
valle ; but, on diminishing this distance, 
‘the repulsion ceased by degrees, and 
gave place to an attraction which, by 
-an accelerated motion, carried the talc 
‘toward the paralfelopiped, and brought 
it speedily into contact with it. This 
experiment, several times repeated with 
different modifications, constantly gave 
the result indicated by the theory. 
In another memoir, continues the 
reporter, M. Laplace has proposed to 
subject to the same analysis the phe- 
nomena of the adhesion of bodies to 
the surface of fluids. When we apply 
a disc of glass on the surface of water 
at rest in a vessel of great extent, we- 
experience, in detaching it, a resistance, 
so much more considerable, as the sur- 
face of the disc is greater. On elevating 
the disk, we raise up, at the same time, 
E above 
