206 Important Chemical Difcoveries in the National Inftitute. [ March, 
One of the moft precious fubitances 
which chemifls of all ages have made 
the obje¢t of theirinveftigation, gold, is 
fearcely ever difcovered on the furface, 
or in the interior of the globé, but is 
found blended with a blackish fand, 
which is alfo metallic, and fufceptible of 
magnetic attraétion. CHAPTAL, in his 
experiments on this fubfiance, made it 
undergo, at different times, the action of 
air, water, caloric, fulphur, carbone, 
acids, alcalies, and various foivents,' 
and from the refults of his different ex- 
periments, concludes, that the magnetic 
fand is a particular modification of iror, 
produced by nature. [See our laf? Number. | 
CuaprTat has alfo applied-the powers 
of chemiftry to his experiments on the 
qualities of the juices, contained in dif- 
‘ferent vegetables. In thefe operations, 
he examined the glutinous juices of many 
euphorbia, thofe of other plants, of the 
fame family, or of different families, the 
‘decoétions of a number of vegetables 
with a ligneous flalk, and the milk of 
varions emulfve grains. He extracted 
thefe juices by experiments, which he 
repeatedly varied, and combining the 
different refults, afcertained the principle 
of union which connects the feveral phe- 
nomena with the original develop:ment 
of the vegetable embryo. His obferva- 
tions alfo tend to caft new light on the 
art of dying. Proceeding hence to higher 
confiderations, he difcloies the origin of 
carbone, one of the three principal ele- 
ments of which vegetable fubftances. are 
compofed; he fhows how it loages it- 
feif in, and circulates through, all the 
-parts.of the plant; and corroborating 
his opinions by the refemblance which 
he traces between the refults of h's pre- 
fent experiments, and thofe produced by 
the fame chemical agents on blood and 
milk, the alimentary juices of men and 
animals, he goes on to inveftigate the 
mode by which nourifhment is performed 
in the. latter. 
Guytow DE MorvEAvu read a me- 
moir.on the refemblance between the 
hyacinth of France, and that of Ceylon, 
and the new. fimple earth which it con- 
tains. 
Thefe hyacinths are found in the brock 
Efpally, or Expailiy, in the department 
of the Haute-Loire. 925 centigrammes 
of cryftals, reduced to powder in an agate 
mortar, were mixed with pot-ath. and 
expofed to a furnzce, in a crucible of 
placina ; part of the fufed mafs was dif- 
f,lved in water, and the remainder was 
entirely taken up by the muriatic acid : 
a feries of experiments was made, the 
refult of which was, that the hyacinth of 
France, like that of Cevlon, confifts of 
a {mall proportion of oxide of iron, filex, 
and more than fix-tenths of its weight of 
a peculiar earth, now known/under the 
name of jargon, zircon, or circonia. 
‘This earth differs from filex in being. 
foluble in the acids, and incapable of 
union with alcalis in the dry way. It is 
not baryt, fince it forms with the ful- 
phuric acid, a falt very difficultly cryftal- 
lized. It is not lime, for lime precipi- 
tates it from its combinations ; neither is 
it magnefia, fince it does not form a 
bitter falc with fulphuric acid, and en- 
tirely refufes to combine with carbonic 
acid: it differs from alumine, in not 
forming alum with the falphurie 
acid. {In a ftate of purity, it is abfo- 
lutely infoluble in -pot-ath, even at the 
heat of ebullition. It has the fingular 
property of accompanying iron, in the 
precipitation of this metal by the pruf- 
fiatess; and a ftill more characteriftic 
peculiarity is, that the carbonated alcalis 
precipitate it from its acid folutions, and 
then re-diffolve it. 
Tessier has been alfo attempting te 
throw new light on the ftamina of vege- 
tables, having feleéted, as the obje&t of 
his refearches, wheat, the moft beneficial 
plant to man. He has contemplated the 
glutinous matter which is produced by 
the farina of corn, and which has been 
called the vepero-animale. He has en- 
deavoured to aicertain the quantum of 
gluten contained in every ipecies or 
variety of corn, the proportion of which, 
more or lefs confiderable, has fo great an 
influence on the goodnefs of bread; and 
after having demonftrated by his experi- 
ments, that the fatnefs of foils has no 
kind of conne€tion with the lefs or 
greater abundance of the glutinous mat- 
ter, he poiats out to the rural economift, 
the courfe he is to purfue, in order to 
attain the objeét he wifhes for. 
‘Trnon laid down the precepts, and 
exhibited the example of a particular 
method of ftudying the organizaion of 
men and animals. He demonitrated the 
utility of confidering the conformation of 
each'of their parts, at the different pe- 
riods of their growth, their perfeétion, 
and their decay, and proceeding to apply 
this method to certain parts in ‘animals, 
which are very hard, and yet very va- 
riable (fuch as. the tooth, and par-icd- 
larly that of hurfes) he deduces a num- 
ber of conclufions fo much the more 
obfervable, as they fatisfaétorily account 
for other facts, already known; but diffi- 
cult to be explained; and, as they muft 
neceflarily 
