
-— 
Aug. 3, 1871] 

agent. 
gas on the large scale by heating hydrate of lime with anthracite. 
We learn from the history of metallurgy that the valuable 
alloy which copper forms with zinc was known and applied long 
before zinc itself was discovered. Nearly the same remark may 
be made at present with regard to manganese and its alloys. 
The metal is difficult to obtain, and has not in the pure state 
been applied to any useful purpose; but its alloys with copper 
and other metals have been prepared. and some of them are likely 
to be of great value. The alloy with zinc and copper is used as 
a substitute for German silver, and possesses some advantages 
over it. Not less important is the alloy of iron and manganese 
prepared according to the process of Henderson, by reducing in 
a Siemen’s furnace a mixture of carbonate of manganese and 
oxide of iron. It contains from 20 to 30 percent. of manganese, 
and will doubtless replace, to a large extent, the spiegeleisen 
now used in the manufacture of Bessemer steel. 
The classical researches of Roscoe have made us acquainted, 
for the first time, with metallic vanadium. Berzelius obtained 
brilliant scales which he supposed to be the metal, by heating 
an oxychloride in ammonia, but they have proved to be a nitride. 
Roscoe prepared the metal by reducing its chloride in a 
current of hydrogen, as a light gray powder, with a metallic 
lustre under the microscope. It has a remarkable affinity both 
for nitrogen and silicon, Like phosphorus, it is a pentad, and 
the vanadates correspond in composition to the phosphates, but 
differ in the order of stability at ordinary temperatures, the 
soluble tribasic salts being less stable than the tetrabasic com- 
pounds. 
Sainte-Claire Deville, in continuation of his researches on dis- 
sociation, has examined the conditions under which the vapour 
of water is decomposed by metallic iron. The iron maintained 
at a constant temperature, but varying in different experiments 
from 150° C. to 1600° C., was exposed to the action of the vapour 
of water of knewn tension. It was found that for a given tem- 
perature the iron continued to oxidise, till the tension of the hy- 
drogen formed reached an invariable value. In these experi- 
ments, as Deville remarks, the iron behaves as if it emitted a 
vapour (hydrogen) obeying the laws of hygrometry. An interest- 
ing set of experiments has been made by Lowthian Bell on the 
power possessed by spongy metallic iron of splitting up carbonic 
oxide into carbon and carbonic acid, the former being deposited 
in the iron. A minute quantity of oxide of iron is always formed 
in this reaction. 
The fine researches of Graham on the colloidal state have re- 
ceived an interesting extension by Reynolds’s discovery of a new 
group of colloid bodies. A solution of mercuric chloride is added 
to a mixture of acetone and a dilute solution of potassium hydrate, 
till the precipitate which at first appears is redissolved, and the 
clear liquid poured upon a dialyser which floated upon water. 
The composition of the colloid body thus obtained in the anhy- 
drous state was found to be (CH3), (CO)2 Hg, Os. The hydrate 
is regarded by Reynolds as a feeble acid even more readily de- 
composed than alkaline silicates. A solution containing only 
five per cent. forms a firm jelly when heated to 50°C. Analo- 
gous compounds were formed with the higher members of the 
fatty kenone series. In the same direction are the researches of 
Marcet on blood, which he finds to be a strictly colloid fluid con- 
taining a small proportion of diffusable salts. 
In organic chemistry the labours of chemists have been of late 
largely directed to a group of hydrocarbons which were first dis- 
covered among the products of the destructive distillation of coal 
or oil, The central body round which these researches have 
chiefly turned is benzol, whose discovery will always be associated 
with the name of Faraday. With this body naphthaline and an- 
thracene form a series, whose members differ by C, H,, and 
their boiling points by about 140°. The recent researches of 
Liebermann have proved, as was before suspected, that chrysene 
is a fourth member of the same series. I may add that ethylene, 
which boils at about 70°, corresponds in composition and boiling 
point to a lower member of the sameseries. Kekulé propounded 
some time ago with great clearness the question as to whether 
the six atoms of hydrogen in benzol are equivalent, or on the 
contrary play dissimilar parts. According to the first hypothesis, 
there can be only one modification of the mono- and penta-de- 
rivatives of benzol; while three modifications of the bi-, tri-, 
and tetra-derivatives are possible. On the second hypothesis, 
two modifications of the mono-derivatives are possible, and in 
general a much larger number of isomeric compounds than on 
the first hypothesis, Such is the problem which has of late 
NATURE 
Tessier de Mothay has also proposed to prepare hydrogen | 

275 
occupied the attention of some of the ablest chemists of Germany, 
and has led to a large number of new and important investiga- 
tions. The aromatic hydrocarbons, toluol, xylol, &c., which 
differ from one another by C Hz, have been shown by Fittig to 
be methyl derivatives of benzol. According to the first of the 
two hypotheses to which I have referred, only one benzol and one 
methyl benzol (toluol) are possible, and accordingly no isomeric 
modifications of these bodies have been discovered. But the 
three following members of the series ought each to be capable 
of existing in three distinct isomeric forms. The researches of 
Fittig had already established the existence of two isomeric 
compounds having the formula Cg H,)-—methyl toluol obtained 
synthetically from toluol, and isoxylol prepared by the removal 
of an atom of methyl from the mesytelene of Kane. The same 
chemist has since obtained the third modification, orthoxylol, 
by the decomposttion of paraxylylic acid. These three iso- 
meric hydrocarbons may be readily distinguished from one 
another by the marked difference in the properties of their tri- 
nitro-compounds, and also by their different behaviour with 
oxydising agents. Other facts have been adduced in support of 
the equality or homogeneity of position of the hydrogen atoms 
in benzol. Thus Hiibner and Alsberg have prepared aniline, a 
mono-derivative from different bi-derivatives, and have always 
obtained the same body. ‘The latest researches on this subject 
are those of Richter. - 
Baeyer has prepared artificially picoline, a base isomeric with 
aniline, and discovered by Anderson in his very able researches 
on the pyridine series. Of the two methods described by Baeyer, 
one is founded on an experiment of Simpson, in which a new 
base was obtained by heating tribromallyl with an alcoholic solu- 
tion of ammonia. By pushing further the action of the heat, 
Baeyer succeeded in expelling the whole of the bromine from 
Simpson's base in the form of hydrobromic acid, and in obtain- 
ing picoline. The same chemist has also prepared artificially 
collodine, another base of the pyridine series. To this list of 
remarkable synthetical discoveries, another of the highest interest 
has lately been added by Schiff—the preparation of artificial 
coniine. He obtained it by the action of ammonia on butyric 
aldehyde (C,H,O). The artificial base has the same composi- 
tion as conitne prepared from hemlock. It is a liquid of an 
amber-yellow colour, having the characteristic odour and nearly 
all the ordinary reactions of ordinary coniine. Its physiological 
properties, so far as they have been examined, agree with those 
of coniine from hemlock, but the artificial base has not yet been 
obtained in large quantity, nor perfectly pure. 
Valuable papers on alizarine have been published by Perkin 
and Schunck. The latter has described a new acid—the anthra- 
flavic—which is formed in the artificial preparation of alizarine. 
Madder contains another colouring principle, purpurine, which, 
like alizarine, yields anthracene when acted on by reducing 
agents, and has also been prepared artificially, These colouring 
principles may be distinguished from one another, as Stokes has 
shown, by their absorption bands; and Perkin has lately con- 
firmed by this optical test the interesting observation of Schunck, 
that finished madder prints contain nothing but pure alizarine in 
combination with the mordaunt employed. 
Hofmann has achieved another triumph in a department of 
chemistry which he has made peculiarly his own. In 1857 he 
showed that alcohol bases, analogous to those derived from am- 
monia, could be obtained by replacement from phosphuretted hy- 
drogen ; but he failed in his attempts to prepare the two lower 
derivatives. These missing links he has now supplied, and has 
thus established a complete parallelism between the derivatives 
of ammonia and of phosphuretted hydrogen. The same able 
chemist has lately described the aromatic cyanates, of which one 
only, the phenylic cyanate (CO, C,H;, N), was previously 
known, having been discovered about twenty years ago by Hof- 
mann himself. He now prepares this compound by the action 
of phosphoric anhydride on phenylurethane, and by a similar 
method he has obtained the tolylic, xylylic and naphthylic 
cyanates. 
Stenhouse had observed many years ago that when aniline is 
added to furfurol, the mixture becomes rose-red, and communi- 
cates a fugitive red stain to the skin, and also to linen and silk. 
He has lately resumed the investigarion of this subject, and hss 
obtained two new bases, furfuraniline and furfurtoluidine, which, 
like roseaniline, form beautifully coloured saits, although the 
bases themselves are nearly colourless or of a vale brown colour. 
The furfuraniline hydrochlorate (C,, Hy, O, N, Cl) is prepared by 
adding furfurol to an alcoholic solution of aniline hydrochlorate 
