44% 
wan for the fufion of filiceous and -argilla- 
ceous ores of iron; yet he never obtained 
a fingle metallic button; and only found 
at the bottom of the crucible a vitrified 
mafs of an opaque black, or a feoria in 
the ftate of crude caft iron. He then at- 
tempted to obtain a malleable button 
by ufing the blow-pipe, taking borax 
for the flux and fupporting the oxide on 
charcoal, but could only procure a fpongy, 
ingot refembling crude caft iron. But 
being placed on a fupport of glafs, the 
oxide fufed at the fecond attempt, the 
fupport was coloured green, and {mall 
grains of iron were feen to pafs firft of 
a dark green colour, then of a bright 
green, and afterwards to difappear in 
€vaporating. There remained on the 
globule only a flight tinge of biackifh 
green. see mer 
As a general refult M. Dodun infers 
that this oxide is entirely deprived of its 
metallic principle, and that its fuper- 
oxigenation renders it reducible and re- 
fractory. He fuppofes that the arts may 
draw advantages from thefe oxides by ufing 
them as pigments. 
It fhould feem that this difcovery may 
be of ufe in this country as there are in 
many parts of it large mafles of iron ftone, 
fome of which are found in the vicinity of 
moft coal mines. It has been long kncwn 
that iron ochres have the fame property 
of forming puzzolana with lime when pro- 
perly roafted ; and a patent as been ob- 
tained for the application of iron pyrites 
to the fame, purpofe. But the novelty 
of M. Dodun’s difcovery is, that poor 
iron ftone is equally fit for this purpofe, 
as the other fubftances mentioned, which 
is of more importance as it is very plen- 
tiful, and may often be procured in fitua- 
tions where the others cannot. Bafalt 
treated in the fame manner has the fame 
property as the puzzolana: the whin- 
ftone, of which the ovoidal paving-ftones 
moftly confift, is of this kind, and is 
found in great abundance here. 
ROYAL SOCIETY OF SCIENCES 
OF COPENHAGEN. 
The clafs of Natural Philofophy had 
propofed the following question: ** Is 
oxygen gas, or any other gafs containing” 
oxygen, abfolutely neceflary for the hatch-’ 
ing of eggs? Is it poffible that eggs can 
be hatched in irrefpirable gafes, and in 
this cafe in what mephytic gas?” 
The Society received an anfwer, written 
in French, with the motto, Num vefcitur 
aura. atherea@? The unknown author 
clearly defctibes the preparations and 
# 
Proceedings of Learned Societiess 
f June ls 
means which he employs for this purpofe. 
The refult of his experiments is, that eggs 
may be hatched in irrefpirable gales. 
This refult- being contrary to the received 
opinions on the animal economy, the 
Royal Society therefore refolved to direét 
every thing requifite “for this object to be 
prepared, and the experiments to be’ res 
peated -by Mcfirs. Von Hauch, Wiborg, 
Herfcoldt, Rahn, Scheele and Bigge. 
Thefe gentlemen accordingly repeated the 
experiments in-the different irrefpirable - 
gefes,.conformably to the method of the 
author and found a very diffiné organiza- 
tion in the eggs; they perceived the rami. 
fications of the veins and of the arteries, 
the pulations of the beart, and in fome 
eggs the members already formed, accord- 
ing as the eggs-had been a longer ora 
fhorter time in the machine. The experi- 
ments were feveral times tried with the 
fame fuccefs ; but they took the precau- 
tion to examine the {tate of the air in the 
recipients under which the-operation took 
place. By means of the eudiometer and 
other telts, they were convinced, that, du- 
ring the hatching, the irrefpirable pafes 
under all the recipients had loft their me- 
phitic quality, and had become more or 
lefs vefpirable. 
The reaton of this fingular phenomenon 
was found in the plafter which the author 
-employs to clofe his recipients, The atmos 
fpheric air, and alfo a portion of oxygen 
gas, penetrated the pores of the plafter, 
and fucceffively found their way.into the 
recipients. This negative experiment de- 
monftrates that the author has‘not hatched’ 
his eggs in irrefpirable gafes as he pres 
tends. 
The commiffioners thought it would be ~ 
interefting to reply to the queftion by dew 
cifive and pofitive experiments. ‘They 
procured a good cement or maftic. They 
afcertained by preliminary experiments 
that there was no paflage for the air at the ° 
temperature requifite for the hatching of | 
eggs. The recipients were filled with ats 
mofpheric air, with oxygen gas, azotic 
gas, hydrogen gas, &c. All thefe reci- 
pients with the eggs were’ placed in a 
hatching-machiae. - At the expiration of 
the neceffary time, the gas in each recie 
pient was examined with the utmoft care, 
and it was found that the gas was of the 
fame quality, that is, atmofpheric gasy 
oxygen gas, azotic gas, hydrogen gas, &ce — 
as previous to the beginning of the experi. 
ments. On opening the eggs the moft — 
diftinct organization was obferved in the © 
eggs, under all the recipients filled with ~ 
atmofpheric air, or oxygen gas, ea 
: oo ‘ a 
