THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [November 11,1871. 
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86 
the oxygen of the air which is not needed to produce 
combustion of the gas, yet which, under the influence of 
x ‘ pressure ” and draught, may commingle with the flame, 
mot only of the Bunsen, hut of every kind of burner. 
'The consequence is, that the two non-luminous (and in 
.this case incombustible) diluents—the nitrogen and the 
•excess of oxygen—mingling in the flame, are heated by 
abstracting heat from the burning gas ; so that it seems 
obvious that the gas-flame cannot acquire the high tem¬ 
perature which it would otherwise possess. 
The flame of the Bunsen burner has hitherto been re¬ 
garded as the hottest of all gas-flames. But this, the 
.referees say,, is not correct: for, in repeated experiments, 
■a platinum wire has melted in the blue part of batwing 
and fishtail flames, whereas the same wire did not melt 
in any part of the Bunsen flame. The special advan¬ 
tage of the Bunsen burner is that it gives a smokeless 
flame, and also that, by the intermixture of air, the gas 
is consumed within the smallest possible space; and 
■ceuteris paribus, the smaller the flame in which a given 
quantity of gas is consumed, the hotter will be the 
flame, more gas being burnt in the same space. At the 
same time, as already said, it seems obvious that owing 
to the intermixture of air with the gas, the flame of the 
Dunsen burner cannot possess as high a temperature as 
would be the case if an equal quantity of gas could be 
burnt pure in an equally small flame. The Bunsen 
burner consumes the gas in the smallest possible space, 
thereby concentrating the heat developed by the 
burning gas; but, on the other hand, the intermixture 
-of air appears in some respects to alter unfavourably the 
■conditions of combustion. 
In all flames like those of gas, of a candle, or a match 
of wood or paper, a portion of the flame is blue. And 
this blue portion is always at the bottom of the flame. 
Any one who examines a burning candle will also ob¬ 
serve that there is a peculiar band of very bright blue 
forming the outermost rim of this lower part of the 
flame. And if a burning spill of wood or a paper-match 
be examined, it will be seen that this bright-blue part of 
the flame is strongest (not only at the bottom but also) 
at the point nearest to the unignited part of the match ; 
i. e. at the point where the substance first) takes fire. 
Doubtless the blue and almost lightless part of all flames 
is produced from the combustion of hydrogen (which 
ignites more quickly than the carbon), and the bright- 
blue rim edging this under part of the flame is due to 
carbonic oxide. By repeated experiments, also, it was 
found that the blue part contains within it the hottest 
point of the flame. 
The upper white portion of gas-flames may be said, 
speaking roundly, to be the only portion of the flame 
•which gives light. How is it composed ? The fact of 
gas-flames smoking shows that some portion of gas may 
pass through the whole of the flame without being per¬ 
fectly consumed; and the upper portion of the flame 
manifestly consists of gaseous atoms which have passed 
through the lower blue portion of the flame unignited, 
■or else which acquire an increased temperature as they 
ascend. As the illuminating power of gas is due to the 
incandescence of carbon, it appears evident that, while 
the free hydrogen burns in the under part of the flame, 
the hydrocarbons burn chiefly in the upper part: and 
the intensity of their combustion is aided by the great 
heat generated by what may be called the" furnace of 
hydrogen below. 
There is a striking difference of appearance between 
gas-flames and what may be called natural flames; e. g. 
of burning coal or of a candle. The latter flames are 
more solid,—they have less blue and more white than 
gas-flames. This is owing, in the first place, to there 
being more carbon in these natural flames than in gas. 
Take the case of a candle, or of the flames from coal 
burning in a grate. In both of these cases the whole of 
the light-giving vapours are consumed in the flame ; 
iwh.ere.as in gas, a large portion of the light-giving va¬ 
pours of coal are lost, being withdrawn by the condensing 
apparatus in the gas-works. It is only the permanent 
vapours of coal that constitute gas,— i. e., one which does 
not condense under ordinary circumstances. But a large 
proportion of the illuminating elements of burning sub¬ 
stances condense readily, and therefore cannot be used 
as gas. In an oil-lamp or a candle, the tvhole of the 
illuminating vapours of the oil and the tallow go to 
form the flame; but in gas a large portion of the illu¬ 
minating constituents of the coal is withdrawn by con¬ 
densation in the form of tar, naphtha, etc.; for, as these 
vapours condense at the ordinary temperature of the air, 
they would, if left in the gas, become solids as soon as 
they cooled, and thereby choke the pipes. This is one 
cause of the difference between natural flames and gas- 
flames : the former are produced by the whole illumi¬ 
nating vapours of the burning substances, whereas in 
gas all the non-permanent vapours are withdrawn, and 
the light is due only to the permanent vapours yielded 
by the coal. 
The effect of the temperature of gas on its illuminating 
power, and how it affects the development of that illu¬ 
minating power in burners, is a question that has been 
little investigated; but, in the main, it has been held 
that the warmer the gas supplied to the burner, the 
greater will be the amount of light obtained compared 
to the quantity of gas consumed. Some experiments on 
this subject were made last year, in the laboratory of 
the University of Munich, in which the burner was at¬ 
tached to a U-tube, immersed alternately in a freezing 
mixture and in a liquid at a high temperature. 
[To be continued.) 
NITRITE OF AMYL. 
Some time since, we gave an abstract of a paper from 
the Medical Times and Gazette which contains some par¬ 
ticulars as to the therapeutic uses of the new remedy, 
nitrite of amyl.* In the Practitioner for October, Dr. 
Talfourd Jones, Physician to the Brecknock County and 
Borough General Infirmary, furnishes some other inter¬ 
esting information concerning its mode of application 
and its effect in some cases in which he has used it with 
considerable success. 
Dr. Jones states that he has now given it experi¬ 
mentally to some fifty friends and patients, and he has 
found that its inhalation invariably causes increased 
frequency of the cardiac pulsation, accompanied by 
flushing of the face, warmth of head, face and neck, and 
perspiration—the warmth and perspiration often being 
general. A pulse of twenty in the quarter-minute will 
often rise in ten or fifteen seconds to forty. It some¬ 
times causes a little breathlessness, or now and then 
giddiness, and in some a feeling of intoxication. 
It may be administered by inhalation, by the mouth 
or by subcutaneous injection. Dr. Jones considers the 
best and safest way to be by inhalation. He usually 
pours five drops upon a piece of lint the size of a crown- 
piece or larger, and holds it close to the nostrils for ten 
or twenty seconds, or until an acceleration of the pulse 
is felt or the face begins to redden. Another plan is to 
drop the nitrite on to a pocket-handkerchief, and then 
hold it to the nose just like chloroform, or it may be in¬ 
haled directly from the bottle. He has never seen any 
bad effect result from its use, but he considers it to be 
an important point that it should be administered with 
great judgment and caution to aged persons or those 
who are the subjects of arterial degeneration. 
Dr. Jones considers that it acts by relaxing muscular 
spasm, and he mentions several cases of spasmodic asthma, 
angina pectoris, colic, etc., in which it gave immediate 
relief. In the case of a young man suffering from an- 
* Phabm. Jouen. 3rd Ser. Yol. I. p. 209. 
