Art. XX. Experiments made in France upon the Use of Distilled Seawater for domestic purposes, and its Effects on the Constitution, when taken as a Beverage.
Art. XX. Experiments made in France upon the Use of Distilled Seawater for domestic purposes, and its Effects on the Constitution, when taken as a Beverage.[25]
In consequence of the great want of good fresh water in many of the maritime parts of France, the government some time since ordered some experiments to be made, upon an extensive scale, in order to ascertain how far seawater, when distilled, could be used with success. Little or no use had hitherto been made of water so prepared, except in long voyages, and chiefly then only as a matter of necessity. There are above two hundred leagues of seacoast in France, where, to the breadth of many miles, the inhabitants are compelled to make use of bad and impure water, which, in many cases, is injurious to the health of themselves and their animals. In similar cases, it was the custom of the ancients to construct cisterns; but these are not only expensive in themselves, but their utility depends upon the quantity of rain that falls; while upon the shores of the most barren places, nature has supplied a variety of vegetable matter, which, when dried, would not only serve as a fuel for the purposes of distillation, but from the ashes of which might be obtained a saline substance, sufficient to repay the expense of collecting, drying, and burning. Thus the fuel for the distillation of seawater would, in reality, cost nothing, while its preparation would employ many individuals, particularly women and children. Before, however, erecting any apparatus for this purpose, it was necessary to ascertain both the utility and salubrity of the water thus prepared.
It is well known that Bougainville, Phipps, Homelin, &c. had employed this water with much success; but they, like most of the chemists of the last age, did not endeavour to imitate the process of nature in all its simplicity, but mixed various substances with the seawater, in order to take away or lessen the effect of the empyreuma arising from the distillation, and which was so unpleasant to the smell and taste. And it is this which in general renders sailors so averse to it, and excites a prejudice very unfavourable to the salubrity of distilled seawater. One of the great objects to be ascertained was, whether this disagreeable smell and taste was peculiar to seawater or arose from the act of distillation.
In the month of July, last year, the king ordered some experiments to be made, upon a large scale, at the three ports of Brest, Rochefort, and Toulon. The instructions given were as follows: That a sufficient quantity of seawater should be distilled to prepare, for the space of a month, bread and other food for a certain number of criminals, who were employed on the works of these ports, and also to supply them with drink, keeping from them during that period every other liquid. Ten or twelve persons at each part voluntarily came forward and offered themselves for the experiment.
The persons employed by government first distilled a sufficient quantity of seawater, without the admixture of any other substance. This produce dissolved soap, dressed vegetables, produced the same appearances, with the aerometer, as that distilled from spring water. There was no difference between the one and the other. But the distilled seawater had always that empyreumatic taste and smell, of which we have before spoken; and it was so strong, that the commission at Toulon called it odeur de marine, and odeur de marecage. But this is not peculiar to seawater, for the result of a distillation of fresh water had always the same taste and smell. Neither of these liquids immediately loses this by being filtered through charcoal; but by being exposed for some time to the air, the distilled seawater loses this unpleasant quality, and then it does not differ from fresh water derived from the purest source; and both have equally stood every chemical test to which they have been exposed. The chemical properties of this water having thus been determined, it remains to give an account of the effects upon the individuals who underwent the experiment. These are the principal results:
Brest. During the first days, those who drank the water complained of a weight upon the stomach. This indisposition, which was the only one they experienced, soon decreased upon taking exercise, and totally went off by an additional ounce of biscuit added to their common ration. One of them, on the 29th day, had a few symptoms, but which he himself attributed to an indigestion, from some bacon he had eaten. Eight individuals drank twenty-five pints a day, rather more than three pints each,—(N. B. The French pint contains very near fifty-seven cubic inches of English measure, and is the regulation size for the claret or Bordeaux bottle; but in general the bottles are rather smaller. The French pint is therefore equal to rather more than nineteen-twentieths of an English quart, wine measure.)
Toulon. The results obtained at the arsenal of this town, were not less decisive or satisfactory. The six persons who made the experiment acquired a greater degree of freshness in their appearance, and were much fatter. Their daily consumption of distilled water was nine pounds (poids de marc) for drink, and eleven pounds for cooking. This is nearly the same relative quantity as those at Brest.