M A N 
M A N 
M A N 
100 
and by Waitz in 1705 ; but chemists in ge- 
neral seem to have paid but very little atten- 
tion to it. The greater number of minera- 
logists, though much puzzled what to make 
«f it, agreed in placing it among iron ores: 
but Pott, who published the lirst chemical 
examination of this mineral in 1740, having 
ascertained that it often contains scarcely any 
iron, Cronstedt, in his System of Mineralogy, 
which appeared in 1758, assigned it a place 
of its own, on the supposition that it consist- 
ed chiefly of a peculiar earth. Rinman ex- 
amined it anew in 1765 ; and in the year 
1770 Kaiin published at Vienna a set of ex- 
periments, in o refer to prove that a peculiar 
metal might be extracted from it. The same 
idea had struck Bergman about the same 
time, and induced him to request of Scheele, 
in 1771, to undertake an examination of man- 
ganese. Scheele’s dissertation on it, which 
appeared in 1774, is a masterpiece of analy- 
sis, and contains some of the most important 
discoveries of modern chemistry. Bergman 
himself published a dissertation on it the same 
year ; in which he demonstrates that the mi- 
neral, then called manganese, is a metallic 
oxide. He accordingly made several at- 
tempts to reduce it, but without success ; the 
whole mass either assuming the form of sco- 
riae, or yielding only small separate globules 
attracted by the magnet. This difficulty of 
fusion led him to suspect that the metal he 
was in quest of bore a strong analogy to plati- 
num. In the mean time Dr. Gahn, who was 
making experiments on the same mineral, ac- 
tually succeeded in reducing it by the follow- 
ing process: lie lined a crucible with charcoal- 
powder.moisteued with water, put into it some 
of the mineral formed into a ball by means of 
oil, then tilled up the crucible with charcoal- 
powder, luted another crucible over it, and 
exposed the whole for about an hour to a very 
intense heat. At the bottom of the crucible 
was found a metallic button, or rather a num- 
ber of small metallic globules, equal in weight 
to one-third of the mineral employed. It is 
easy to see by what means this reduction was 
accomplished. The charcoal attracted the 
oxygen from the oxide, and the metal re- 
piained behind. The metal obtained, which 
is called manganese, was farther examined by 
llseman in 1782, Hielm in 1785, and Bind- 
Jjeim in 1789- 
Manganese, when pure, is of a greyish- 
white colour, and has a good deal of bril- 
liancy 7 . Its texture is granular. It has nei- 
ther taste nor smell. Its hardness is equal to 
that of iron. Its specific gravity is 7.000. 
It is very brittle ; of course it can neither be 
hammered, nor drawn out into wire. Its te- 
nacity is unknown. It requires, according to 
Morveau, the temperature of 160° Wedge- 
wood to melt it ; so that, platinum excepted, 
it is the most infusible of all the metals. 
When reduced to powder it is attracted bv 
the magnet, owing probably to a small por- 
tion of iron from which it can with difficulty 
be parted. 
11. Manganese, when exposed to the air, 
attracts oxygen more rapidly than any other 
body, phosphorus excepted. It loses its 
lustre almost instantly, becomes grey, violet, 
brown, and at last black. 'These changes 
take place still more rapidly if the metal is 
heated in an open vessel. 
This metal seems capable of combining 
with three different proportions of oxygen, 
and of forming three different oxides, the 
white, the red, and the black. 
The protoxide or white oxide may be ob- 
tained bv dissolving the black oxide of man- 
ganese in nitric acid by adding a little sugar, 
i lie sugar attracts oxygen from the black ox- 
ide, and converts it into the white, which is 
dissolved by the acid. Into the solution pour 
a quantity of potass; the protoxide precipi- 
tates m the form of a white powder. It is 
composed, according to Bergman, of 80 
parts of manganese and 20 of oxygen. When 
exposed to the air it soon attracts oxygen, 
and is converted into the black oxide. 
The deutoxide or red oxide may be ob- 
tained by dissolving the black oxide in sul- 
phuric acid, without the addition of any com- 
bustible substance. When black oxide of 
manganese, made into a paste with sulphuric 
acid, is heated in a retort, a great quantity of 
oxygen gas comes over, while the oxide, 
thus deprived of part of its oxygen, dissolves 
in the acid. Distil to dryness, and pour wa- 
ter upon the residuum, and pass it through a 
liitre. A red-coloured solution is obtained, 
consisting of the sulphat of manganese dis- 
solved in water. On the addition of an al- 
kali a red substance precipitates, which is the 
red oxide of manganese. According to Berg- 
man it is composed of 74 parts of manganese 
and 26 of oxygen. T his oxide likewise at- 
tracts oxygen when exposed to the atmo- 
sphere, and is converted into the black 
oxide. 
The peroxide of black oxide of manganese 
exists abundantly in nature ; indeed it is al- \ 
most always in this state that manganese is 
found. It was to the black oxide that the 
appellation manganese itself was originally : 
applied. It may be formed very soon by ex- I 
posing the metal to the air. This oxide, ac- 
cording to Fou'rcroy, is composed of 60 
parts of manganese and 40 of oxygen. When 
heated to redness in an earthen retort it gives 
out abundance of oxygen gas, which may be 
collected in proper vessels. By this operation 
it is reduced nearly to the state of red oxide, j 
If it is exposed to the. air, and moistened oc- 
casionally, it absorbs a new dose of oxygen ; 
and t hits the same process may again be re- : 
peated. No oxygen gas can be obtained 
from the white oxide : a proof that its oxy- 
gen is retained by a stronger affinity than the 
additional dose of oxygen which constitutes 
the black oxide. Seguin has observed, that 
in some cases the black oxide ot manganese 
emits, before it becomes red, a quantity of 
azotic gas. When long exposed to a strong 
heat it assumes a green colour. In that state 
it is whitened by sulphuric acid, but not dis- 
solved. A very violent heat fuses this oxide, 
and converts it into a green-coloured glass. 
III. Manganese does not combine with hy- 
drogen. When dissolved in sulphuric acid a 
black spongy mass of carburet of iron is left 
behind. Hence it has been supposed capa- 
ble of combining with carbon ; but it is more 
probable that the carbon is combined with 
the iron, which is almost always present in 
manganese. It seems pretty clear, however, 
that carburet of iron is capable of combining 
with this metal, and that it always forms a 
part of steel. 
Bergman did not succeed in his attempt to 
combine manganese with sulphur; but he 
formed a sulphureted oxide of manganese, 
by combining eight parts of the black oxide 
with three parts of sulphur. Tt is of a greet? 
colour, and gives out sulphureted hydrogen 
gas when acted on by acids. It cannot be 
doubted, however, that sulphur is capable of 
combining with manganese; for Proust has 
found native sulphuret of manganese in that 
ore of tellurium which is known by the name 
of gold ore of Nagyag. 
Phosphorus may be combined with manga- 
nese by melting together equal parts of the 
metal and of phosphoric glass ; or by drop- 
ping phosphorus upon red-hot manganese. 
The phosphuret of manganese is of a white 
colour, brittle, granulated, disposed to cry- 
stallize, not altered by exposure to the air, 
and more fusible than manganese. When 
heated the phosphorus burns, and the metal 
is oxidized. 
IV. Manganese does not combine with ei- 
ther of the simple combustibles. 
V. Manganese combines with many of, the 
metals, and forms with them alloys which, 
have been but very imperfectly examined. 
it unites readily with copper, 't he com- 
pound, according to Bergman, is very mal- 
leable, its colour is red, and it sometimes be- 
comes green by age. Gmelin made a num- 
ber of experiments to see whether this alloy 
could be formed by fusing the black oxide of 
manganese along with copper. He partly 
succeeded, and proposed to substitute this 
alloy instead of the. alloy of copper and arse- 
nic, which is used in the arts. 
It combines readily with iron ; indeed it 
has scarcely ever been found quite free from 
some mixture of that metal. Manganese 
gives iron a white colour, and renders it 
brittle. It combines also with tin, but scarcely 
with zinc. 
It does not combine with mercury nor 
with bismuth. Gmelin found that manga- 
nese cannot he alloyed with bismuth without 
great difficulty ; and that it unites to anti- 
mony very imperfectly. Chemists have not 
attempted to' combine it with gold, platinum,, 
silver, nickel, nor cobalt. 
A I. The affinities of manganese, and of its 
white and red oxides, are, according to Berg- 
man, as follows : 
Manganese. Oxide of manganese . 
Copper, Oxalic acid. 
Iron, Citric, 
Gold, Phosphoric, 
Silver, 'Tartaric, 
Tin. Fluoric, 
Muriatic, 
Sulphuric, 
Nitric, 
Sac lactic. 
Succinic, 
Tartaric, 
Lactic, 
Acetic, 
. Prussic, 
Carbonic. 
MANGIFERA, the' mango-tree , a genus 
of the monogynia order, in the pentandria 
class of plants, and in the natural method 
ranking with those of which the order is 
doubtful. The corolla is peutapetalous ; the 
plum kidney-shaped. There are three spe- 
cies, the p”rincipaT of which'is a native of 
many parts of the East Indies, whence it has 
been transplanted to Brazil, and other warm 
parts of America. It grows to a large size; 
