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THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[Jane 8,1872V 
of H 2 for C 17 , when HI and P act on morphia or codeia, 
takes place before, and not after, the final polymerization ; 
even polymerization to dicodeia could not precede this 
addition of of IT, as the product obtained from that 
polymeride has only H added on for C t -. 
The following formulae show clearly the difference in 
the action of hydriodic acid and phosphorus on codeia 
and its polymerizes. 
Alkaloid. Temperature. Formula of Product. 
10l° ... 8(C 17 H 19 NO s + H s ) + 12HI. 
Codeia 
,, ... 
Dicodeia 
Tetracodeia 
n0°-115° ... 8(0, 
up to 130° 
up to 120° 
up to 130° 
_ 7 H 19 NOj + H.. 
8(C 17 H 18 N0 3 + H 
) + 12HI-4H 2 0. 
> 0 . 
Prom which it is 
between tetracodeia 
3 -0) + 12HI-4H 2 
. 8(C l7 H”NO' + H) + 9HI-4H a O. 
. 8(C l7 H 10 NO 3 ) +10HI —2H a O. 
clear that dicodeia is intermediate 
and ordinary codeia. From the 
fact that 4HI for 8 (C 17 ) are added on in the case of the 
first product before the elimination of 4H 2 0, as in the 
second substance in the list, it may be inferred that the 
action is not a true substitution of iodine for hydroxyl; 
analogous facts have been observed in the chlorinated 
substances obtained by the action of HC1 on codeia and 
morphia, the first action being apparently a direct 
addition of the elements of HC1, the subtraction of the 
elements of H 2 0 taking place at a later stage. 
PHENOMENA ASSOCIATED WITH THE HYDROGEN 
FLAME. 
BY W. F. BARRETT. 
In a recent number of ‘ Nature,’ * Mr. W. F. Barrett 
has recorded some extremely interesting researches upon 
some phenomena associated with the hydrogen flame, 
one of the results of which appears to be that the 
statement current in the manuals of chemistry, that 
hydrogen burns with a blue flame, will in future have 
to be altered. The following is a sketch of some of the 
phenomena met with, but we must refer our readers to 
the paper itself for further details and the conclusions 
which the author draws from his experiments. 
For the purpose of studying these phenomena free 
from disturbing causes,^ Mr. Barrett recommends that 
the gas should be purified by passing into a gasholder 
through a solution of potash, and then through a solu¬ 
tion of perchloride of mercury or nitrate of silver; that 
it should be conducted to a platinum, or, preferably, a 
steatite jet, through red or black india-rubber tubing, 
and that it should be burnt in a perfectly dark room, 
amid calm and dustless air. The flame so obtained is a 
faint reddish-brown colour, invisible in daylight, but in 
a. dark room showing a stream of luminosity more than 
six times longer than the flame of the burning hvdrogen. 
In many cases, wdien solid bodies, such as marble, 
into contact 
brought 
chalk, granite, gypsum, etc., are 
with the flame, phosphorescent effects are produced. 
Sand-paper gives a vivid green phosphorescence, show- 
ing a perfect section of the hollow flame, and lasting 
several seconds. No such effect is produced by coal-gas 
or olefiant or marsh-gas, but oxygen given through coal- 
gas shows it well. 
One remarkable phenomenon, which has been studied 
also by M. Wffrtz, is the deep blue and glowing image, 
the exact size and shape ot the hollow flame, that in¬ 
stantly appears upon such an object as a white plate or 
block of ^ marble when brought into contact with the 
flame. This effect ceases immediately upon the removal 
of the flame; it also becomes less distinct, and finally 
ceases, if the flame be directed repeatedly to the same 
spot. After many experiments, Mr. Barrett arrived at 
the conclusion that this phenomenon was in every case 
due to the presence of sulphur. It does not occur when 
a chemically clean surface is used. After such a surface 
has been exposed a short time to London air, which con¬ 
tains sulphate of ammonia, it is produced; but not when 
the surface is simply exposed to country air, or kept under 
cover. To sulphur, indeed, arising from various sources,, 
such as vulcanized tubing or the decomposition of the 
sulphuric acid, he attributes the blue colour generally 
associated with the hydrogen flame. 
As an instance of the delicacy of the hydrogen flame 
as a test for detecting the presence of sulphur, Mr. 
Barrett states that although pure precipitated silica 
gives no blueness with the flame, yet if one grain of 
milk of sulphur be mixed with five hundred grains of 
silica, and one-hundredth of a grain of this mixture be 
thrown on the surface of pure water or chemically clean 
platinum foil, the blue colour is produced upon bringing, 
the hydrogen flame in contact with it. The fingers, too, 
immediately after washing, show no colour if brought 
for a moment into the flame ; but if they touch a white 
india-rubber tube ever so lightly, they will show a vivid 
blueness, and any substance with which they come in 
contact will show traces of it. Some sulphates and sul¬ 
phides,—sulphate of ammonium or alum, for instance,— 
show the blueness, and are evidently decomposed by the 
flame ; sulphate of soda does not. Sulphuric acid gives 
a splendid brilliant and persistent blue. 
The presence of the least trace of phosphorus is re¬ 
vealed by the production of a vivid green light. Tin 
and its alloys give a fine scarlet colour; or if there be a 
trace of sulphur, a lovely purple. If phosphorus also be 
present, there may be obtained a green belt encircling a 
rich blue, then a purple zone, and finally a glowing 
scarlet at the root of the flame. These colours are not 
imparted to the flame, but occur on the surface ; neither, 
are they produced when the combustion of the hydrogen: 
is complete, as in the upper part of the flame. 
With gases, the result is different, the whole flame 
being tinged wdth the colour imparted to it. A mere 
trace of hydrochloric acid gas imparts a reddish brown 
colour; ammonia imparts a yellow colour, and bums 
freely. Carbonic acid gives a lilac tinge, probably due 
to its decomposition, and the production and combustion 
of carbonic oxide. 
The author thus briefly sums up the results of his 
experiments:— 
“ 1. That the combustion of hydrogen exhibits some 
physical peculiarities, and produces phosphorescence on 
many substances with which it comes in contact. 
“2. That the blueness so often seen in a hydrogen 
flame is due to the presence of sulphur, derived either 
from the vulcanized rubber tubing, or from atmospheric 
dust, or from the decomposition of the sulphuric acid 
spray from the generator. 
“ 3. That a flame of hydrogen forms an exceedingly 
delicate re-agent for the detection of sulphur or phos¬ 
phorus, and possibly also of tin. 
“ 4. That many sulphates, and also carbonic acid, are 
apparently decomposed by a hydrogen flame. 
“5. That a hydrogen flame is further a test for’the 
presence of some gases, notably carbonic acid. 
“ 6. That these results are capable of practical appli¬ 
cation.” 
* ‘ Nature,’ April 18th, 1872, p. 482. 
METROPOLITAN CHEMISTS’ DEFENCE 
ASSOCIATION. 
The business of the above Association was finally 
concluded on Wednesday last, at the Covent Garden. 
Hotel, by the presentation of an elegant work of art to 
Mr. E. B. Yizer. The following inscription, borne on 
one of its panels, expresses the feelings of its donors:— 
“ Presented to E. B. Yizer, Esq., by his fellow com¬ 
mitteemen of the Metropolitan Chemists’ Defence Asso¬ 
ciation, and a fewffricnds, as a trifling acknowledgment 
of his efficient services as Secretary.” 
It was at first intended to limit the list of contributors 
strictly to the members of the committee; but a few 
other gentlemen, who had come into contact with Mr. 
Yizer, and who greatly appreciated his character and 
his labours, had insisted on being permitted to add their: 
names. - 
