132 Foreign Literature and Science. 
A memoir of Luiscius, (Rotterdam, 1798,) on the putre- 
faction of vegetable and animal substances, states, 1st, that 
these substances, in contact with water, are entirely decom- 
posed, if the air have free access; 2d, that the decomposi- 
tion is singularly accelerated by air ; 3d, that under — 
circumstances, (air and water having free access,) much n 
tric acid is produced, and a little ammonia ; 4th, that thibse 
substances putrefy in different times in the following order ; 
urea, gluten, animal gelatine, muscular fibre, starch, white of 
eggs, gum, sugar, vegetable fibre, &c.— Ibid. 
ate oe of ammonia in argillaceous minerals.—It is 
the TE Se M. Bouts, of Perpignan, from his experi- 
ents and enel ton: that the argillaceous Fd of miner- 
als} is owing to the presence of ammonia. — s found it in 
pipe clay, impure gypeum of vario ais forsatone: steatitic 
earths, anterior to the presence of 0 organised bodies, &c. 
When these substances are moistened with a solution of 
ar. potash, the argillaceous odor is generally increased, 
in that ¢ =i a glass wet with hydro-chloric acid occa- 
rote white vapors when held near them. Litmus paper, 
slightly re Ricced, and placed over these earths, thus moist- 
ened, has its blue color restored, 
Argillaceous odor has been gen oral s ascribed to the ox- 
ide of iron, but it is difficult to conceive how this substance 
can render inert substances odorous. The presence of am- 
monia in these minerals may account for the odor sd) The 
he 
ammonia becomes. the vehicle of the peculiar a 
materi 
An analogous ctncidiieast occurs in musk, tobacco, &c. 
which when perfectly dry, are almost inodorous but when 
moistened with a weak solution of ammonia, give out their 
characteristic odor.— Ibid. 
28. Magaciieis.- Scebeck, in making new researches 
on the property w which the metals have of diminishing the 
number "af oscillations of the magnetised needle, determined 
the different degrees of this force in each met etal. He used 
-a.needle two and one eighth inches long, suspended by a fibre 
of silk, at the that et of three lines over -metalli 
one = een the two amplitudes of 45° and 
