"These gases and vapors (alluding to emanations given off from the ground during earthquakes) exert an influence on the barometer, which does appear to be indirectly affected by the earthquake. Then, similar properties also may occasion that uneasiness which animals are said to evince before any such event. Thus, according to the accounts of some writers, rats and mice leave their holes, alligators seek the dry land, quadrupeds snuff the ground, and manifest such signs of the impending calamity that in countries where earthquakes are common, the inhabitants take the alarm in consequence, and escape from their houses. It is right, however, to add, that more recent authorities dispute altogether the correctness of these statements." Dutton doubts the ability of animals to foretell coming earthquake shocks. But that the lower animals do exhibit signs of fear at the approach of an earthquake has been repeatedly asserted by good observers. Hamilton, who made a careful examination of the neighboring country during the great earthquake at Calabria, asserts that horses and oxen during the shocks extended their legs widely in order to avoid being thrown down, "and that hogs, oxen, horses, and mules, and also geese, appeared to be painfully aware of the approach of the earthquake of Calabria; and the neighing of a horse, the braying of an ass, or the cackling of a goose, even when he (Hamilton) was making his survey (after the occurrence of the great earthquake shock), drove the people out of their temporary sheds in expectation of a shock." It is asserted that birds appear to be especially sensible to a coming earthquake shock. That geese will quit the water in which they were swimming before the earthquake and will not return to it. It is quite possible that these birds with their heads immersed in the water can hear the distant murmurings long before they become audible in the air. Von Hoff makes the following statement: "It has been remarked that at such times (immediately before the coming of an earthquake shock), domestic animals showed a decided uneasiness, dogs howled mournfully, horses neighed in an unusual manner, and poultry flew restlessly about. These latter phenomena might easily be produced by mephitic vapours, which often ascend to the surface of the earth before the breaking out of an earthquake." Mallet states that there is abundant evidence that earthquake shocks, even when not of very great intensity, produce nausea in both men and women. This would seem natural, since, as everyone knows, until one is accustomed to sea-voyages, merely to be tossed to and fro by the motion of the waves results in the production of sea-sickness.