2800. ] 
culture cannot, be ‘carried on to any pro- 
fit; that foil in which the plant delights, 
#s arich fandy loam, three feet or more in 
depth. 
‘The ground being firt made {mooth, is 
divided into beds four feet wide, with al- 
ternate alleys, half as broad again as the 
beds; the reafon of this extraordinary 
breadth of the alleys will'appear prefently. 
In each alley is to bea fhallow channel for 
the convenience of irrigating the whole 
field, &c. that part of the alley that is not 
otherwife occupied, may be fuwn with te- 
gumes. The madder feed is fown broad- 
caft inthe proportion of from 25 to 30 lbs 
per acre, about the end of April. Ina 
fortnight ov three weeks the young plants 
begin to appear, and from this time to the 
month of September, care muft be taken to 
keep the ground well watered and free 
from weeds. If the plants are examined 
in autumn, they will be found furrounded 
with fmajl yellew offsets at the depth of 
two inches, and early in September, the 
earth from the alleys is to be dug out and 
laid over the plants of madder to the height 
of two or three feet; with this the firft 
year’s operation finithes. 
The fecond year’s work begins in May, 
with giving the beds a thorough weeding ; 
and care muft betaken to fupply them with 
plenty of water during fummer. In Sep- 
tember, the firf{ crop of feed will be ripe, 
_at which time the fems of the plants may 
’ 
be mown down, and the roots crenn nt 
few inches with earth, taken as before out 
of the alleys. 
The weeding fhould take place as early 
as poffible-in the {pring of the third year, 
and thecrop, inftead of being left for feeds, 
may be cut three times during fummer for 
green fodder, all kinds of cattle being re- 
markably fond of it. In Oétober, the 
roots are taken up, the offsets carefully 
feparated, and immediately ufed to form a 
new plantation; and the roots, after being 
dried, are fold either without further pre- 
pavation, or ground to a coarfe powder, 
and {prinkled with an alkaline ley. The 
roots’ lofe four fifths of their weight in 
drying, and the produce of an acre is 
about 2ooolbs weight of dry faleabie 
madder. 
: — 
An Account? of the PROCEEDINGS of 
the Cuass of PHysrcaL- and Ma- 
' THEMATICAL SCIENCES, during the 
Sift Quarter of the 8th Year, read at 
the Public Sitting of the 4th of January; 
 T800 by C. Cuvier. 
E. Guyton has prefented a‘table of 
direct combinations of forty-two 
chemical elements 5 3 that is to fay, of fub-« 
-' National Inftitute. 
‘S75 
ftances which chemifts have not yet been 
able to decompofe, and which ’ “they regard 
as fimple fubftances, until the contrary 
be proved. 
Thefe forty-two RaNeancee) » combined 
only two at atime, give 861 different 
combinations; of which wedo not yet 
know even one half. If we combine them 
in a triple or quadruple feries, paying at 
the fame time attention to the conftituent 
parts of allthe combinations, we fhall find 
the number of the latter increafe to a de- 
sree which overpowers the imagination. 
One might, at firft, be induced to re- 
gard our ignorance of the greater part of 
thefe combinations, as a proof of the im- 
perfection of the fcience; whilft, in faé, 
it is from the immenfe progrefs which it 
has lately made that we have difcovered 
even the poffibility of thefe combinations. 
Formerly no one conjectured the exift- 
ence of thefe elements, nor the combina- 
tions of which they are fufceptible; and 
every time when a new element, ora fub- 
ftance fimple fo far as our prefent inftru- 
ments are capable of afcertaining, is dif- 
covered, the chemift has to afcertain the 
properties of more than forty fingle and 
a much greater number of compound com- 
binations. His tafk thus daily ata 
in an incalculable proportion. 
Among the fubftances.with which she: 
mifiry' has been enriched in our own time, 
the ‘principal are fome femi-metals, one 
of which has been named by its difcoverer, 
M. Kiaprorg, of Berlin, xranite, from 
the planet Uranus, or Herfchell’s planet ; 
following the example of the ‘lehorrailts 
who had denominated the common metais 
from the feven ancient planets. 
. Cuampeéavx is the firtt who found 
the ore of uranite in France. All the de. 
tails of this difcovery have been communi- 
cated tous by C. LELIEVRE. 
Chemifts have given the appellation: 
affinity to that principle by which different 
fubftances tend to unite with each other ; 
and to afcertain the various modifications 
of this principle is the peculiar object of all 
their refearches.. The fcience of chemif- 
ry, cannot be regarded as complete, until 
we poffefs.a orate of the degrees of affinity 
of each fubftance with every other in all 
given circumftances. 
The principal difficulty in forming fuch 
a table, arifes firdm the affinities not pre- 
ferving the fame order under all circum- 
ftances., It has been long known, for in- 
ftance, that this order varies according to 
the different degrees of heat; but feveral 
other caufes,'to which chemifts had not 
hitherto fufhiciently attended, contribute 
to the fame effect. 
c, Boe 
