[_February 15, lb73. 
652 THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
analogy becomes apparent, the vibrations of the flame 
being selected by its tube and raised to a note of a defi¬ 
nite pitch. Further, an open organ pipe vibrates in 
two halves when sounding its lowest note, the centre 
being a node, a place where the air is not in lateral 
motion,, but where its density only is changing - , but an 
open, pipe is also capable of vibrating in 4-6-8, etc., 
divisions, and sounding what are called its harmonics or 
overtures, in which case the nodes alter their position 
and number. [This was effectively shown with an 
organ pipe haying, three little gas jets at its side, com¬ 
municating - with its interior by means of membranes; 
on sounding its fundamental note the centre one was 
extinguished while the two side ones remained burning - ; 
on the first harmonic being sounded the two side-jets 
were extinguished, while the centre one remained 
alight.] The same result is obtainable with a musical 
flame, several notes being produced from one tube. 
[The connection existing between a sounding, and an 
exalting, or resounding body was here treated of, and 
by a.series of experiments it was shown that a definite 
relation, depending - upon the length of the sound wave, 
must be maintained between the embouchure of an organ 
pipe and the column of air enclosed in the pipe,—between 
a tuning fork and its box or cylinder of air,—also, be¬ 
tween a flame and the tube which surrounds it; but in 
the case of the flame, on account of its great mobility, 
it .was found to be capable sometimes of determining 
this relation itself, the size of the flame altering the 
pitch of the note, and being also capable sometimes of 
even accommodating itself to variously lengthened tubes.] 
During Dr. Tyndall’s experiments he observed the 
extreme sensitiveness of a flame on the point of singing 
to external sound. Just before the point at which a flame 
would begin to sing in its tube, it stands, as Dr. Tyndall 
puts it, “ on the edge of a precipice” over which any 
sound in unison with the note it would emit if singing, 
pushes it, and.it at once begins to sound. The external 
impulse for this effect need not be strong, but it must be 
in unison, or,, at least, so near unison as to produce the 
effect of musical beats with the flame itself, which is a 
result of the interference of the sound waves. [A flame 
was here introduced into a tube and placed in this con¬ 
dition, which, on . being sung - to from a distance of 
several yards, or with the back turned, immediately com¬ 
menced to sound ; the note emitted by the flame wa 3 D 
sharp, and it was found to be perfectly indifferent to D 
•natural sounded on a flute, but the D sharp of the same 
instrument immediately caused it to sing, although the 
interval between these two notes corresponds to only 
half a tone.] 
Musical flames may be enlarged indefinitely, provided 
a due relation be kept between the flame and the tube, 
some very large.tubes being caused to sound and giving 
rise to notes similar to those obtained from 16-feet 
organ pipes. Considerable credit is due to Count 
Schaffgotsch, of Berlin, for the independent discovery 
of some of these effects. 
All the flames hitherto experimented with have been 
enclosed in tubes ; some of them have been shown to be 
very sensitive to certain external sounds, but the general 
title “Sensitive Flames has been applied to phenomena 
more especially connected with unenclosed, or naked 
flames. 
Professor Leconte, of the United States, observed in 
.1858 the pulsation of two fish-tail gas flames, under the 
influence of certain musical notes emitted from various 
instruments, and also observed that these pulsations were 
not perceptible until the gas flame approached its flaring- 
point, and were further not produced by other external 
noises. This effect was again observed independently 
by Mr. Barrett, at the Royal Institution in 1866, who, 
together with Dr. Tyndall, was able to pursue the ex¬ 
periments to a much greater extent. A jet of gas 
issuing,from almost any orifice becomes sensitive when 
the pressure is increased to a point just below that at 
which it would flare ; some jets are extremely sensitive to 
a whistle, dropping down at the sound from a height of 
about twenty, inches to about twelve inches ; others are 
most responsive to a hiss or chirp. 
These effects are not the result of the impact of air, 
which may be easily proved, but depend entirely upon 
the sonorous vibrations. A gas flame issuing from a jet 
under pressure is probably thrown into a state of vibra¬ 
tion on its passage through the orifice ; if this vibration, 
be.very pronounced, the flame flares, but just below this 
point, the flame is sensitive to such vibrations as are 
synchronous with its own, and which would, if added to 
those it already possesses, cause it to flare ; thus it is seen 
that a sensitive flame flares only during the continuance 
of certain sounds, these sounds being equivalent to an 
increase of pressure. The nature of the sound causing 
this effect.is by no means a matter of indifference; a 
hiss or chirp is very effective, also the sound of the 
letter S, the. vowels having hardly any effect upon such a 
flame; shrill notes give a greater result than low ones. 
If the orifice be very small, and the pressure correspond¬ 
ingly great, extreme and surprising results are obtained. 
[A remarkable flame of this kind was exhibited, about 
twenty inches high; at the sound of a hiss it dropped 
to half its height, the crumpling - of paper, the rustle 
of a dress, produced the same effect; a musical-box 
caused it to dance to the tune, and the effect of the 
ticking of a watch was distinctly seen; further a -watch 
was placed in the focus of one concave mirror and the 
flame in the focus of a similar mirror, the slight ticking 
of the watch was thus reflected through a distance of 
about eight feet, yet its effect upon the flame was 
distinctly visible.] It was incidently mentioned that 
many ot the so-called facts of spiritualism were not 
more wonderful than the behaviour of this flame, which, 
without the key to the explanation, would itself appear 
almost supernatural. 
In conclusion, attention was called to the fact, that 
flames were not the only things sensitive to slight impulses. 
The continual observed change produced in nature 
being, probably, due to infinitesimal movement amongst 
the molecules of which bodies are composed. This 
movement—utterly outside the bounds of our perception 
—being evident to us sometimes, as one of those forces 
which we recognize as '‘modes of motion.” Innu¬ 
merable illustrations of this appropriation and exaltation 
of exceedingly small motion occur. For instance, the 
growth ot plants is dependent mainly upon the power 
possessed by them of shaking apart the carbonic acid 
gas present in the air, and of utilizing its carbon in the 
building up of their tissues and stems. This power is 
conferred by sunlight and by sunlight alone. The great 
luxuriance of vegetation almost everywhere, would seem 
to require the whole power of the sun to be expended in 
this. direction only. But on analysing - the sun’s rays, 
we find only a portion of them to be capable of conferring 
this power ; and it has been estimated that at any given 
time the chemically active portion of these rays pre¬ 
sent in sunlight only amounts to the ^oobuoM of 
the total energy of the sun given out at that time. 
Fermentation, putrefaction, decay, are all due to the 
presence and growth of the most minute germs of living 
matter, far beyond the power of the best microscopes to 
reveal. The “Germ Theory” of disease now gaining 
ground so rapidly, holds for one of its principal tenets, 
that the body to contract a contagious disease must be in 
a certain state of harmony and sympathy with the dis¬ 
turbing cause—like a sensitive singing flame, only sus¬ 
ceptible to those vibrations which coincide with its own. 
Lastly, to take an illustration! from that profession with 
which this Association is more intimately connected. It 
would appear that medicine itself is only availing when 
the system is in harmony with it, and capable of re¬ 
sponding to its counteracting influence. 
At the close of the lecture, which was frequently ap¬ 
plauded throughout, the President said, “After the 
