816 THE FIGURES OF EQUILIBRIUM OF A LIQUID MASS 
between the action of the configurative forces and that of the vibrations, and it 
may be readily conceived that then the transformation of the vein, which being 
only a phenomenon of instability may be displaced by slight causes, will cause 
the collective dilatations and restrictions to retrograde or advance, so as to estab- 
lish very soon the above coincidence and thus allow the concurrence and entire 
freedom of the two systems of action. 
8. These principles being established, we shall see emerge from them one 
by one all the modifications undergone by the vein through the influence of the 
vibrations. * 
Let us first remember that when the vein is abandoned to the sole action of 
the configurative forces the velocity with which the transformation is accom- 
plished remains very small to a quite considerable distance from the contracted 
section, which gives to the corresponding portion of the vein a calm and limpid 
aspect; in the second place, that, further on, the dilatations acquiring a marked 
and more rapid development, the vein appears to grow larger up to the point 
at which the masses become isolated; and, finally, that beyond that point the 
diameter of the vein, a diameter which is that of these masses, is sensibly uni- 
form. (2d series, § 70.) 
Let us suppose now such a vein, and produce, in proximity with the apparatus, 
the sound we have been considering in all that precedes. Under the influence 
of this sound each division quitting the contracted section in a more advanced 
phase of transformation, (§ 5,) and the transformation moreover advancing from 
that phase with a greater velocity than it would have done under the sole in- 
fluence of the configurative forces, (§ 6,) it necessarily results that this transfor- 
mation will be completed in less time; consequently each division will attain 
the state of an isolated mass ata less distance from the orifice, and thus the 
continuous part will be rendered shorter. And since the dilatations are more 
developed from their inception, we sce, in the second place, that the apparent 
thickness of the limpid portion of the vein, a thickness which, at each point in 
the length of that limpid portion, is evidently that which the dilatations have 
acquired at the moment of passing it, will be augmented. In the third place, 
the excess of transverse velocity which the transformation receives from the 
vibrations, and which continues as acquired velocity, must necessarily cause the 
horizontal diameter of the successive masses to exceed that of the spheres 
which these masses tend to constitute, so that the masses will become flattened 
in the vertical direction. But we perceive that this horizontal extension and 
vertical flattening render the capillary pressure, at the circumference of the 
mass, superior to that of the points near the axis, and that thence arises an in- 
creasing resistance which ends by destroying the transverse velocity. Then 
the differences of pressure will act freely, and the mass will return upon itself 
to attain its figure of equilibrium, that is, the spherical figure; but the phe- 
nomenon, being effected with an accelerated velocity, cannot stop at this last 
figure, and the mass will be contracted in the horizontal direction while it is 
elongated in the vertical direction, until the increasing resistance which results 
from new inequalities between the pressures has annihilated the acquired ve- 
locity ; the mass being now urged by the differences of pressure which have 
produced that resistance will again return towards the spherical figure, which 
it will once more surpass, and extending itself a second time in the horizontal 
direction will become flattened in the vertical one; after which it will recom- 
mence the same series of modifications, and will continue these oscillations of 
form as long as its fall continues. 
Thus we eXplain very simply, for the case of unison with the sound which 
the impact of the discontinuous part would occasion, the facts recited in Nos. 1, 
2,3 and 4, of §3. Only, as the extremity of the continuous part of the vein 
occurs about the mid-length of the first expansion, and consequently is little 
distant from the point corresponding to the first of the maxima of thickness of 
