58 NATURE 
[May 15, 1902 
peaceful mountain drove sixteen hundred million cubic 
yards of itself to sucha height that many of the falling 
fragments struck the ground with such velocity that they 
were buried out of sight. 
To know the extent to which the phenomena accom- 
panying the eruption of Pelée find a parallel in those 
exhibited by her predecessors will be determined in the 
future. The probable loss of life, which it is to be hoped 
has been over-estimated, is given at 40,000. Whatever 
this number may be, it has been suggested that the same 
might have been reduced had the inhabitants of the 
stricken district taken warning from the slight earth- 
‘quakes by which the great eruption was preceded. But 
may we not ask whether small earthquakes are not 
so frequent in the Windward Islands that were the 
inhabitants to fly with every tremor the Antilles would 
be depopulated ? 
Although the last great eruption of Pelée, which was 
one of frightful violence, occurred in 1851, statistics 
which do not take account of mere tremors credit the 
{sland of Martinique, in an interval of twenty-six years, 
with 148 disturbances, whilst the Lesser Antilles 
generally are, during the same interval, credited with 
nearly 1200. 
That volcanic outbursts are usually preceded by 
slight earthquakes is well known. How very slight 
these may be is testified by the tall and not too sub- 
stantial buildings in Naples near the base of the almost 
continually erupting Vesuvius. Unfortunately, the occur- 
rence of slight earthquakes is very much more frequent 
without, rather than with, volcanic outbursts. Many of 
the 1000 earthquakes which are annually recorded in 
Japan, two or three of which would shatter a London, 
are felt round the base of volcanoes, but it is only on 
rare occasions that they have been followed by disaster. 
Could science devise a means by which increasing 
pressure beneath a volcanic area could be measured, or 
could the crust of the same be rendered transparent, 
until familiarity ended in contempt, such areas would in 
all likelihood be sparsely populated ; but so long as we 
cannot distinguish between the shakings which announce 
the abortive attempts of volcanoes to establish an Open- 
ing and those tremblings and gurgitations which precede 
attempts that are successful, people will go on living as 
before. 
One writer predicts great storms to follow the 
eruption. In August, 1891, a hurricane passed over 
Martinique, to be followed by an earthquake. The 
hurricane months for Martinique are July, August, 
September and October, when no doubt we shall have 
records of hurricanes both before and after earthquakes. 
In considering the probable cause of this West Indian 
disaster, attention is drawn to the fact that the Lesser 
Antilles as seen on a chart are a group of islands 
running approximately from south to north, forming the 
outcrops of a suboceanic ridge. The western side of 
this ridge is steeper than the eastern, with the result that 
off Martinique, for example, at a distance of 5 or 6 miles 
there are soundings of 1200 fathoms, whilst on the 
opposite side such depths are not even found at distances 
of 50 miles off shore. 
The steepness of this fold is such that earthquakes 
might be expected to originate along its western frontier, 
whilst volcanoes would occur along its ridge. Now it is 
chiefly along this western frontier that the cables pass. 
Those of Martinique, of which there are six, radiate from 
Fort de France. One goes northwards 12 miles, to end 
at the ill-fated St. Pierre. Three others also pass north- 
wards to Guadeloupe, Dominica and St. Thomas. 
Another goes southwards to Paramaribo, and the last to 
St. Lucia, St. Vincent and other places. 
Notwithstanding the existence of so many cables, 
communication with Martinique, and later with St. 
Vincent, was interrupted. At St. Pierre the cause of 
NO. 1698, VOL. 66] 
this was no doubt due to the avalanche of mud and lava 
which overwhelmed the town and roadstead. The cause 
of interruptions out at sea would be sought for in seismic 
convulsions, but of such disturbances of any magnitude 
there is no evidence. Since 8 a.m. (Martinique time) on 
the 8th, when St. Pierre was overwhelmed, until the 11th, 
seismographs in Great Britain have been at rest. That 
small earthquakes occurred is known, and it is just 
possible that some of these caused landslides sufficient to 
bury and damage the cables running along and across 
the steep suboceanic slopes described. 
The cause of these earthquakes and the volcanic out- 
break of Mont Pelée and of the Soufriére in St. 
Vincent—at which the last great eruption took place in 
1812—probably results from some widespread rearrange- 
ment in the fold, the ridge of which is represented by 
these islands. The geological evidences pointing to 
elevations and depressions amounting to as much as 
12,000 feet, and all within late Tertiary times, are found 
in the Barbados and other parts of the West Indies. 
If we assume that earthquakes are accelerations in these 
orogenic processes, and volcanic outbursts indicate that 
pressure has been relieved along the foldings they create, 
one inference is that the terrible disasters in the West 
Indies announce that a change has taken place in the 
configuration of the ridge which above the surface of 
the water is known as the Lesser Antilles. 
Whatever may be the scientific inferences in connection 
with the great catastrophe, the situation it has created, 
which Byron might describe as one in which 
‘* Sires have lost their children, wives 
Their lords, and valiant men their lives,” 
commands the heartfelt sympathy of the civilised world. 
J. MILNE. 
DOES CHEMICAL TRANSFORMATION 
INFLUENCE WEIGHT? 
N NATURE (vol. Ixiv. p. 181, 1901) I directed attention 
to experiments by Heydweiller (Drude Avnm., vol. v. 
p. 394) from which he inferred that some chemical trans- 
formations, such as the solution of copper sulphate in 
water, were attended by real, though minute, changes of 
weight, and I pointed out certain difficulties involved in 
the acceptance of this statement. In connection with 
another subject, it has lately occurred to me that such 
changes of weight would really be in opposition to the 
laws of thermodynamics, and I propose now briefly to 
sketch the argument from which this opposition appears. 
It is known! that by suitable arrangements the disso- 
lution of salt may be effected reversibly at a given 
temperature. During the process, a certain amount of 
work is gained and a certain amount of heat at the given 
temperature has to be supplied. In the reverse process, 
of course, an equal amount of work has to be performed 
and an equal amount of heat is recovered. The temper- 
ature being given, these operations are not affected (it 
is assumed) by the height above the earth’s surface at 
which they may be supposed to take place. 
Conceive now that the temperature is uniform through- 
out and that the materials are initially at a low level and 
in one state (A). Let them be raised to a high level and 
there be transformed into the other state (B). Subse- 
quently let them be brought down to the low level and 
transformed back into state A. The reverse transforma- 
tions above and below compensate one another thermo- 
dynamically, and 7/ the weights are the same in the two 
states, so do the operations of raising and lowering. But 
if the weights in states A and B are different, the cycle 
of operations may be so executed that work zs gained. 
1 “*Qn the Dissipation of Energy,” NATURE, Xi. p. 454, 1875 5 “‘ Scientific 
Papers,” vol. i. p. 238. 
