Meteorology is a science of so much general concern, that it seems to be incumbent upon every member of society to aid in augmenting the stock of facts, which the labours of ingenious and scientific men have already accumulated on that subject. Under this impression I propose to devote the following paper to some observations on salt winds or storms, as they have occurred in this country and in Europe—a subject, which although presenting many phenomena of a more than temporary interest, has as yet excited but little attention. Indeed, the opportunities for observation have occurred so rarely as readily to account for its having in a great measure escaped the philosophical acumen of the present age.
It must have been early observed that the atmosphere in the vicinity of the sea frequently becomes impregnated with saline materials; but the first and only account of a salt storm that I have met with, is to be found in the Transactions of the Linnæan Society of London. The 8th volume of that work gives an interesting narration of the effects of a storm of this description, which occurred in England, in January, 1803. It was occasioned by an east wind, which blew for some days, and which, in its passage over the ocean, had imbibed large quantities of salt water, which were afterward deposited upon the land. In most cases these depositions proved fatal to the plants and vegetables which received them. So extensive were the effects of this singular storm, that they were felt in the vicinity of London, at a distance of about seventy miles from the ocean, and in all the intermediate country. In most instances, the leaves of the plants, which suffered from it, appeared as if they had been scorched, and in some places even the tops of the branches mortified. A storm of the same kind took place in England, in February, 1804; and the memoir states, that Sir Joseph Banks had noticed another some years before in Lincolnshire.[55]
A storm attended with similar effects occurred in this country in 1815, and vented its fury upon the eastern states. It commenced on the 23d of September, between eight and nine o'clock, A. M. with the wind from the east. In about two hours the wind shifted to southeast, and blew a perfect hurricane. The extended devastation which ensued, is still in the recollection of every person. The tides rose from nine to twelve feet higher than ordinary, and in many of the principal cities and towns along the coast of New England, churches, houses, bridges, wharves, and in some instances valuable citizens, were buried in one common ruin. In less than three hours the gale abated, and before sunset there was a perfect calm. Such were the more striking features of this tremendous gale—but other effects were observed more peculiarly interesting to the philosopher. At New-London, Salem, and other places, both on the coast, and several miles in the interior, the air was found to be loaded with salt; and the leaves of many trees appeared, a few hours after the storm, as if they had been scorched. Besides this effect upon vegetables, there were additional evidences of the saline quality of the wind. At Salem and some other places an incrustation of salt was perceived on the windows, and the fruit in several gardens had a perceptible taste of salt on their surface. At New-London it was remarked that the air in the eddies was extremely hot and suffocating.
Other facts of a similar nature might be collected, but these it is presumed are sufficient to characterize the state of the atmosphere during that storm.
Several interesting inquiries arise from the consideration of the foregoing facts.
1. In what way does the salt exist in the atmosphere in these storms? On this point there are two different opinions. The most prevalent is, that it is merely the spray of the sea driven onward by the force of the wind. This opinion has received the sanction of Sir Joseph Banks,[56] and also of Sir Humphry Davy, if we may judge from an incidental expression in his Agricultural Chemistry.[57] Another opinion[58] is, that muriate of soda is continually rising into the atmosphere from the surface of the ocean, and that the air, in all maritime situations, is thus constantly more or less impregnated with salt. The most striking fact in support of this doctrine, (so opposite to the commonly received views on the subject of the evaporation of sea water) is the actual existence of muriate of soda in the rain and snow which fall in the vicinity of the ocean.[59] The experiments of Vogel and Bouillon Lagrange, on the distillation of sea water, are also in favour of the position, that salt may be carried into the air in the ordinary process of evaporation. On distilling salt water they found a considerable quantity of muriate of soda in the receiver.[60]
Admitting the correctness of these experiments, still it is not easy to conceive, how they will account satisfactorily for the large quantities of salt found in the air during the storms under consideration.
Whichever of these solutions may be adopted, it is unquestionably a fact that salt does, in some way or other, exist in the atmosphere in the neighbourhood of the sea.