:

letter, printed 1550: a book not commonly to be had, but which I have in my collection. Indeed, in the dedication of this book, which is to Edward VI. we difcover a colon but, as this is the only one of the kind throughout the work, it is plain this ftop was not established at this time, and fo warily put in by the printer or if it was, that it was not in common ufe. Thirty years after this time, in that fenfible and judicious performance of Sir Thomas Elyot, entitled, The Governour, imprinted 1580; we fee the colon as frequently introduced, as any other ftop; but the femicolon and the admiration, were ftill wanting, neither of thefe being vifible in this book. In Hackluyt's voyages, printed 1599, we fee the first inftance of a femicolon: and, as if the editors did not fully apprehend the propriety of its general admiffion, it is but fparingly intro

duced. The admiration was the laft ftop that was invented, and feems to have been added to the

reft, in a period not fo far diftant from our own times.

Thus we fee, that thefe notes of diftinction came into use, as learning was gradually advanced, and improved: one invention indeed! but enlarged by feveral additions. Nothing is more probable, as we can trace them no higher than the 15th century, than that the thought was monaftic. The monks, however ridiculous in fome things, have obliged pofterity with others, truly valuable. Learning, fuch as it was, did not want advocates in this age. If Walfingham, a Benedictine monk of St. Alban's, in this century, wrote the Hiftoria brevis, a work much efteemed at that time, and was diftinguished for his literary accomplishments; 'tis fomething more than conjecture to attribute this invention to him.

Mr. Duhamel's method of preferving the health of Seamen.

FTER feveral obfervations

A on the difference of places

whofe fituation is more or less wholefome, M. Duhamel concludes in general, that rifing grounds, and exposed to the wind, are the most wholefome; that thofe fituate near tide, fresh or falt water, are not fubject to the epidemies that infect fhips; that the fea is not the cause of these epidemies; that the feamen are more exposed to them, when they anchor in roads, furrounded by mud, marshes, and sheltered from the wind; that, when their health obliges them to go on fhore, they fhould be compelled to return on board for the night; or, if this cannot be conveniently effected, fhould be kept at a diftance from marfhy grounds, and not permited ever to encamp, or to lie without good tents, fet up in dry, high and open places.

To discover the particular caufes of infection in ships, M. Duhamel lays down this general principle: that the different qualities of the air, the vapours that humect, the exhalations that penetrate it, influence, to a great degree, the health of the animals that breathe it. Nothing but malignant vapours, or putrid exhalations in the air, can occafion thofe dreadful contagions that lay wafte cities, and fometimes provinces. The more the air is debarred of a free circulation, the inore it is fuceptible of impreffions from the caufes that alter and corrupt it.

Now all thefe inconveniencies concur to infect the air in fhips, efpecially in the hold of a fhip. It there becomes thick, and its thickness does not permit the perfpiration of animals that breathe it, to discuss and diffipate it. Whence it happens, that the warmth of this confined air is more fenfible than that of the exterior air, and its elasticity is prodigiously weakened. It has not, therefore, that degree of condenfation, that freshness, that motion, which makes it fo favourable to refpiration. This may be evinced from the accidents that happen to a bird shut up under a bell, where the air it breathes cannot be renewed. Between decks, and in the holds of fhips, provifions contract heat, ferment, and fend forth exhalations; of which the volume, ftench, and malignity are augmented by the like produced by the dung of animals, the fmell of their wool, their refpiration and tranfpiration, and the vapours exhaled from the putrid waters in fhips and in the fink, and even by the bitumen exhaled from the sea.

If the fhip's crew are attacked by any fickness, the causes for infecting the air are ftill more multiplied, During voyages into cold, and much more into hot countries, feamen meet with new fources of diforders. The changes of air and climate are the more dangerous by their indifcretion in braving, and even provoking their pernicious impreffions. Laftly, falt aliments, though less fubject to corrupt, yet,

by

by being hard of digeftion, bring on a multiplicity of difeafes, especially the fcurvy. These are the enemies M. Duhamel endeavours to deftroy. He first proposes precautions a-, gainst their attacks by preventing them, perfuaded, that it is always eafier to guard againft difeafes, than to cure them; or that, if they cannot be entirely avoided, their violence may, in a great measure, be checked or abated.

These precautions are: i. To admit none aboard, but fresh and healthy failors, and well provided with all neceffaries, in linen and cloaths, to keep themfelves clean, Sick, fatigued, ill-cloathed failors are, in ships, a fource of contagion: 2. To clean frequently the fink; to fweep and fcrub, especially on the infide, all the upper parts of the hip, and particularly the poft of the fick and cattle-fold. All fhould be carefully washed; but this ought to be only during the heat of the day, that it may diffipate the moifture before night, Cleanliness in the failors, and keeping the fhip from all filth, infection, and every thing productive of putrid exhalations and vapours, cannot be fuffi ciently attended to. 3. To purify and renew, as much as poffible, the air in the hold, and under decks, For this purpose are used the vent holes, the wind-fleeve, bellows, and principally Dr. Hales's ventilator.

fhips. Therefore the vents for introducing the pure air cannot be placed too low, nor those for letting out the infected vapours, too high and, if they were too narrow, the vapours would find in them à fric tion, which must obftruct, and tannot be conquered by their levity. As to the other machines, M. Duhamel propofes fome methods for making their play more eafy, and

Vent-holes are only apertures; through which the infected air may efcape. Some obfervations are neceffary to direct their use. Vapours are lighter than pure air, and their levity determines them to afcend through the vent given them. This is a general principle, that regulates the form and ufe of all the machines for renewing the air of VOL. II;

their action more effectual.

Fire is another agent, which may ferve the fame purposes: it rarifies the ambient air, and the vapours it is loaded with. This rarefaction augments confiderably their levity, and confequently accelerates their going out. Prefumes are alfo reckoned as a means for purifying the air of fhips. The author alledges fome examples of very troublefome and obftinate fainting fits, wherein the smell of vinegar alone produced the most falutary effects. This vir tue he attributes lefs to the ftimula ting action of vinegar, than to the impreffion it produces on the air the fick perfons breathe: "For, fays he, there are none but have found fome pleafure in breathing the va pour of vinegar on days difpofed for ftormy weather; wherein the air being lefs fit for refpiration, one is obliged to fetch frequent and profound refpirations; and thus it is fufficiently proved, that it is necef fary to fprinkle good vinegar be tween the decks, and efpecially in the apartment of the fick." However it seems probable, that the effect is almost as tranfient as falutary; that is, that the falubrious quality communicated by vinegar to the air, is not fo durable as the cafe it procures to the fick.

The vapours of burning fulphur continues our author hinder fermen E é

tation

tation, and confequently corruption, even in the liquors that are moft difpofed to ferment, fuch as wine, beer, &c. It is allowed that these vapours ferve to difinfect the merchandize that come from corntries fufpected of contagion. Thofe captains of fhips are therefore to be commended, who, from time to time, burn priming powder steeped in vinegar between decks, or who perfume the decks with vinegar poured upon a red-hot ball. M. Duhamel prefers the afperfion of vinegar to its vapour, whereof the finoak is difagreeable, and they be hurtful, if 100 ftrong; for indeed the fmell of vinegar is more grateful than breathing its vapour; and he alfo counfels, in certain roads, when the weather is fair, to perfume with the vapour of fulphur the decks and bread-rooms. Care, at the fame time, fhould be taken to guard against all accidents of fire; and the ventilator of Dr. Hales, a bellows fo powerful for pumping air, would not be lefs fo, in diffufing the perfumes throughout all parts of the fhip. If any difagreeable fmell remained, it might be eafily diffipated, by going about with a red-hot iron ladle, filled with aromatic drugs of little value, as juniper-berries and fuch like.

From all this practical doctrine, M. Duhamel concludes, "That the hold, where the air is more corrupt than in any other part of the fhip, fhould never be the lodgment of the fick, except in the time of an engagement. He affigns them a place where there are no hatches from the hold nor the lower deck, because the air iffuing from these places is almoft always very unwholfome; and advises, in a parti

cular manner, thofe that are in good health, to make no use of the wearing apparel and the hammocks of the fick, contagious maladies being chiefly communicated by cloaths. "In the time of a plague, it has been obferved, fays he, that whole families have preserved themselves from the contagion, by fhutting themselves up in their houses, tho' they received their provifions from infected perfons, who fometimes fell dead whilft they converfed with them from their windows; whereas at the fame time, a single rag would communicate the plague. Of this, adds he, I have a very decifive proof in the contagion that deftroyed fo great a number of cattle in France and elsewhere. One of our farmers preferved all his cows, by keeping them fhut up in a stable, and by hindering his domeftics to go into infected stables, and those of his neighbours, whofe cattle died, to come into his."

It is true, all these precautions for keeping fhips from being infected, are an addition to the feamen's toil ; but they need not be deemed fuch when found highly expedient for obtaining the great ends_required from their fervice. M. Duhamel proposes likewife fome subftitutes to the ordinary food of seamen; but as the victualling of fhips, particularly thofe of war, is provided for as the wisdom of a government thinks moft proper, we fhall not here touch upon that article.

When ships are arrived at their place of deftination, M. Duhamel recommends, that their stay should be as fhort as poffible in rivers and muddy ports, fheltered from the wind, and known to be unwhol

fome.

fome. He alfo advises to avoid places where the fea is too calm; to abide only where there is good anchorage; to quit, from time to time, the road, and cruize about, in order to exercise the feamen; to place the land hofpital far from vallies, marfhes, and ftagnant waters; to distribute prefervatives a gainst fickness to the foldiers, that repair at night to their tents; to furnish them with fresh provifions in fruits, pulfe, fish, &c. This care will be particularly neceffary in the torrid zone: cold countries require a peculiar treatment in cloathing, exercife, regimen, &c. and failors ftruck with cold fhould be kept from the use of fpirituous liquors, till they are made to receive a certain degree of warmth.

Methods for rectifying the french and corruption of fresh waters.

GR the ftock of fresh water, by long

REAT inconveniency happens but too often at fea, when

ftanding, contracts a naufeous fmell, and is often foul with maggots or worms. To apply, therefore, proper and experienced remedies, in order to correct the fame, the following methods are prescribed :

Take a glafs-veffel, or bottle, and fill it up to the neck with falt; then pour fome oil upon the falt, and ftop well the aperture of the veffel with lime, to hinder any water from penetrating. Let this veffel fall, fo as to hang in the midst of a ciftern, or hogfhead full of water: no putrefaction will happen in the water, though it should stand ever fo long. Some quickfilver may be added. When water begins to grow pu

trid, it may be fufficiently purged, by throwing in a handful of falts and, if falt is wanting, fea-water. For this reafon the feamen at Venice, in Italy, when bound on a long voyage, take their fupply of water from St. Nicholas's well, which, by being near the fea, is impregnated with falt, and on that account continues long pure and wholefome, the brackish taste being fcarce, after a few days, perceptible. We read of the like in the fcriptures, to have been done by the prophet Elifha; who, in Jericho of Palestine, by throwing falt into a fountain, made the waters potable, which before were brackish and putrid. If the water begins to ingender maggots, they are killed by throwing in lime. Any of the ingredients used for the clarifying of wine may be applicable towards the purifying and preferving of water.

A description of a cork waistcoat.

R. Dubourg,. a gentleman

MR

very fond of fwimming, but fubject to the cramp, was led to confider of fome contrivance to fe cure to himself the pleasure of that exercife, without danger. For this purpose he has invented a cork waistcoat, composed of four pieces of cork, two for the breafts, and two for the back, each pretty near in length and breadth to the quarters of a waistcoat without flaps; the whole is covered with a coarse canvas, with two holes to put the arms through; there is a space left between the two back pieces, and the fame betwixt each back and breaft piece, that they may fit the eafier to the body. By this means the waistcoat is open only before, and E e z

may