SCIENTIFIC SUMMAET. 
209 
the scientific experience of these gentlemen ? At a remote period of their 
student days they were required to he present at not more than sixty chem- 
ical lectures, and sixty hours of the most elementary laboratory practice ; 
in such work boys in the Grammar Schools of Birmingham and Man- 
chester could excel them. Even the little knowledge then gained has 
by this time faded away, and they could not, oif-hand, establish the 
difference between sulphate of zinc and Epsom salts, much less the presence 
of alum in bread, or bromide in iodide of potassium. Adulterators may con- 
tinue their evil practices, relying in cases where detection may ensue that the 
criticism of an able chemist will so damage the evidence as to render con- 
viction impossible. A humbling picture of a Local Government Board en- 
gaged in electing an analyst was lately afforded by a report of the proceed- 
ings in a recent copy of the “ Times.” The request of the medical man 
that he should be authorised to spend not more than 100/. in fitting up a 
laboratory with the necessary apparatus for his chemical work was 
“received with much laughter.” A vestryman stated that he possessed 
a laboratory in which he could do almost anything, which cost only 20s. 
The Action of Sodium on Aniline. — x^t the meeting of the “ Chemical 
Society ” on Feb. 6, Dr. H. E. Armstrong said that he was induced to lay 
before the society the results of his experiments on this subject some years 
ago, as Messrs. Merz and Weith had recently stated that sodium had no 
action on aniline. This was correct for temperature below the boiling-point 
of aniline ; but when the two substances are heated in a sealed tube to 200^^ 
the sodium disappears, hydrogen is evolved, and a colophonium-like sub- 
stance produced, which appears to be a mixture of — 
rCeH, 
Na 
H 
and N 
iNa. 
It darkens when exposed to the air, and is decomposed by the action of 
I water with formation of sodium hydrate, and reproduction of aniline. With 
methyl- aniline the action is only partial even at 250°, and with ethyl-aniline 
there is no action even at 300°. The simultaneous action of potassium and 
carbonic anhydride on aniline gives rise to potassium carbonate and diphenyl 
carbamide — 
, The latter substance, however, is not alwa 5 ’’s produced, and even under 
favourable circumstances the amount is but small. 
A strongly decolourising animal charcoal . — Herr Dr. Granger describes this 
in the “ Bayerisches Industrie und Gewerbe-Blatt ” for December last. The 
common powdered bone-black is first mixed with from four to six times its 
bulk of a solution of from four to five per cent, of crystallised carbonate of 
Goda, and boiled therewith for some time ; next it is washed by decantation, 
and after that, treated with a large excess of dilute hydrochloric acid, 
sufficient not only to dissolve the carbonate, but also the phosphate of 
lime it contains. (In order to see whether enough acid had been 
added, a small sample of the previously-filtered fluid is tested by means of 
; ammonia, which, when added in slight excess, should not produce a tur- 
' bidity.) When the mineral matter is removed, the charcoal is thoroughly 
i VOL. XII, — NO. XLVII. P 
