12

Chemical Notices from Foreign Sources. {oy a aps:
borne out by the fag that the different reflecting angles of
the different metals tried did not influence the result ; ig
vas purely, then, confined to some a&ion in the ray
tself (shown to be polarised, &c). (2) This would
iseem to) result in the smaller amplitude of the waves,
when of course the lesser would get where the greater
sould not ; this is proved by the violet succeeding to the
Slue.~I am, &c., i
D. G. CLirp.

would, doubtless, defray their expenses, but such examiners
should only have advisory powers. They might point out
{0 an inventor where they considered his invention weak,
ut he should still have the full privilege of patenting his
invention and taking the consequences of his a&.—I am,
&c., FRANK.

TAR DISTILLERS ». GAS COMPANIES.
To the Editor of the Chemical News.
Sir,—~In your article on this subje& in your last number
you do not treat the tar distiller with your usual justice
when ‘you assert that he, unlike other manufacturers, has
not been alive to the advantages of improvements in the
processes of his business, and that few industries have
suffered more in remaining so long in the background for
want of scientific aid and dire®ion. The success of the
Gas Light Company with their tar works at Beckton,
which you prophecy may possibly rival those of the Cie.
Parisienne at some future time, and which are now actually
on a much larger scale, does not warrant you, I think, in
leciding so emphatically that the tar distillation of the
‘uture must be taken out of the hands of tar distillers and
slaced in those of gas companies.
I freely admit that there are tar distillers who are jogging
an in the old ruts despite the great progress that has been
made in the different improvements of the different processes
 of late years, but these men are in every case in a
very small way of business, with very limited capital to
carry out experimental work or improvements, even when
shey have the technical knowledge to do so; but I contend
that these men have in the past been as successful and
sfficient distillers, and more s0, than managers of small
provincial gas works would have been if they had had this
‘ndustry in charge.
The: larger tar distillers of England and Scotland, I
tontend, will compare favourably with any other body of
manufacturers, either as commercial men, or as possessing
:he technical knowledge of their business, Those of them
who have not had scientific training themselves generally
sngage scientific assistance to ensure their working in the
dest manner and to improve on old processes.
That English distillers are not behind our French neighours
 in adopting a new process or manufacturing a new
product is evidenced by one instance, viz., the manufacure
of anthracene, as this produ@ was manufactured commercially
 by English distillers some considerable time before
:he Cie. Parisienne made it, although they had the assistance
 of their talented chemist, M. Audouin.
In conclusion, I would point out that the success of the
Beckton Tar Works, so far from justifying you in your
strictures on English tar distillers, on the contrary, points
lo the opposite conclusion, as the works were designed by
a tar distiller for the company, and are now managed by
1 gentleman who, I believe, has been brought up to the
ar distilling business.—I am, &c.,
TAR DISTILLER.

CHEMICAL NOTICES FROM FOREIGN
SOURCES,

NoTE.~All degrees of temperature are Centigrade, unless otherwise
expressed, ° °

Comptes Rendus Hebdomadaives des Séances, VAcadimie
des Sciences. No. 22, May 31, 1880.
An Automatic Electric Lamp.—M. Jamin.—This
memoir cannot be intelligibly abstracted without the actompanying
 illustrations,
Heat of Combustion of the Principal Gaseous
Hydrocarbons.—M. Berthelot.—The author gives for
formene, 213°5; ethylene hydride, 388-8; ethylene, 341-4;
acetylene, 318'1; methyl oxide, 3442; propylene hydride,
5560; propylene, 507'3; allylene, 466'5." The author
concludes that the heat of combustion of a hydrocarbon
8 never equal to that of its elements,
Synthesis of Citric Acid.—E. Grimaux and P, Adam,
—The authors prepared dichlorhydrin by means of glycerin
 and sulphur chloride, and ‘oxidised it by means of
potassium bichromate and sulphuric acid. * The symmeric
 dichloraceton thus obtained was purified by combina-‘ion
 with sodium bisulphite, and then heated in the waterrath
 with concentrated hydrocyanic acid. The cyano-di-:hlor-aceton
 was treated with hydrochloric acid; the pro.
lu@ distilled in a vacuum, and exhausted with ether.
The dichlor-acetonic acid obtained was saturated” with
sodium carbonate, and heated with 2 mols. potassium
:yanide in a concentrated solution. The liquid contain
jodium  dicyan-acetonate which was saturated with
jaseous hydrochloric acid, heated in the water-bath for
ifteen hours, and distilled in avacuum. From the residue
.he citric acid was extracted by careful treatment with
nilk of lime.
Researches on the Albuminoid Matters of the
Crystalline Lens and Non-Identity of the Solible
Portion with Egg and Serum Albumen.—A. Béchamp,
—The soluble albuminoid matters in question are phacosymace,
 a substance which remains soluble in water after
it has been precipitated by alcohol. The solution, at a
sertain state of concentration begins to coagulate at 55%
It fluidifies starch paste. The solution in: hydrochloric
acid, takes a violet colour, after being heated for a few
seconds to the boiling-point, Crystal albumen becomes
insoluble in water after precipitation by alcohol, but this
property is not manifested instantaneously. Both these
bodies are thrown down in a plumbic combination by
basic lead acetate, but these Precipitates, unlike those
‘ormed by egg and blood albumens are not decomposed
ay carbonic acid.
Telephone with Magnetic Super-excitation.—M.
Ader.—The new telephone is founded on the principle
that if a slender blade of iron or steel is placed before the
doles of a magnet, it is much more strongly acted upon
f there is placed behind it a piece of soft iron than if thig
8 not the case. Thus a greater sensibility is obtained by
slacing in front of the diaphragm of a common Bell's
.elephone, an iron disc pierced in its centre, with a hols
sorresponding to the mouth of the apparatus.

ACTION OF A NARROW SLIT ON LIGHT.
To the Editor of the Chemical News.
S1r,—I have just been reading “ Effects of Light Passing
Through a Slit,” by Lieut..Com. Michelson. It seems to
ne that no great difficulty obtrudes itself if we apply the
vertical and horizontal theory of waves in light. The
article closes by saying, ‘the experiments in any case
seem to prove (I) that a very narrow slit polarises light,
as described, and (2) that it lets the shorter waves of light
pass more freely than the longer ones.” This is just what
we should expect had the premises been put before us.
{1) The rays are in our plane only, the narrowness preventing®
 those at right angles getting through: this is
— — — Ee  — ————
* Or supposing the planes at all angles, it only allows one to pass:
thus the width ig obtained.