cation from one cavity of the heart to the other from growing up; whence it has been thought fuch dogs might become amphibious. It is alfo believed that this circumftance has existed in some divers for pearl; whofe children are faid to have been thus kept under water in their early infancy to enable them afterwards to fucceed in their employment.

But the most frequent distinction of the amphibious animals, that live much in the water, is, that their heart confifts but of one cell; and as they are pale creatures with but little blood, and that colder and darker coloured, as frogs and lizards, they require lefs oxygen than the warmer animals with a greater quantity and more scarlet blood; and thence, though they have only lungs, they can ftay long under water without great inconvenience; but are all of them, like frogs, and crocodiles, and whales, neceffitated frequently to rise above the surface for air.

In this circumftance of their poffeffing a onecelled heart, and colder and darker blood, they approach to the ftate of fifh; which thus appear not to acquire fo much oxygen by their gills from the water as terrestrial animals do by their lungs from the atmosphere; whence it may be concluded that the gills of fish do not decompose the water which paffes through them, and which contains fo much more oxygen than the air, but that they only procure a small quantity of oxygen from the air

which is diffused in the water; which also is further confirmed by an experiment with the air-pump, as fish soon die when put in a glass of water into the exhausted receiver, which they would not do if their gills had power to decompose the water and obtain the oxygen from it.

The lamprey, petromyzon, is put by Linnæus amongst the nantes, which are defined to poffess both gills and lungs. It has feven spiracula, or breathing holes, on each fide of the neck, and by its more perfect lungs approaches to the ferpent kind; Syft. Nat. The means by which it adheres to stones, even in rapid ftreams, is probably owing to a partial vacuum made by its refpiring organs like fucking, and may be compared to the ingenious method by which boys are feen to lift large ftones in the street, by applying to them a piece of ftrong moift leather with a ftring through the centre of it; which, when it is forcibly drawn upwards, produces a partial vacuum under it, and thus the ftone is 'fupported by the preffure of the atmosphere.

The leech, hirudo, and the remora, echeneis, adhere strongly to objects probably by a fimilar method. I once faw ten or twelve leeches adhere to each foot of an old horse a little above his hoofs, who was grazing in a morass, and which did not lofe their hold when he moved about. The bare-legged travellers in Ceylon are faid to be much infefted by leeches; and the fea-leech, hirudo muricata, is faid to adhere to fifh, and the remora is faid to adhere

to fhips in fuch numbers as to retard their progrefs,

The refpiratory organ of the whale, I fuppofe, is pulmonary in part, as he is obliged to come frequently to the furface, whence he can be pursued after he is ftruck with the harpoon; and may nevertheless be in part like the gills of other fish, as he feems to draw in water when he is below the furface, and emits it again when he rifes above it,

NOTE VI.-HIEROGLYPHIC CHARACTERS.

So erft as Egypt's rude defigns explain.

CANTO I. 1. 351,

The outlines of animal bodies, which gave names to the conftellations, as well as the characters used in chemistry for the metals, and in aftronomy for the planets, were originally hieroglyphic figures, ufed by the magi of Egypt before the invention of letters, to record their discoveries in those sciences.

Other hieroglyphic figures feem to have been defigned to perpetuate the events of hiftory, the discoveries in other arts, and the opinions of those ancient philofophers on other subjects. Thus their figures of Venus for beauty, Minerva for wisdom, Mars and Bellona for war, Hercules for ftrength, and many others, became afterwards the deities of

of Greece and Rome; and together with the figures of Time, Death, and Fame, constitute the language of the painters to this day.

From the fimilarity of the characters which defignate the metals in chemistry, and the planets in aftronomy, it may be concluded that these parts of science were then believed to be connected; whence aftrology seems to have been a very early fuperftition. These, so far, constitute an univerfal vifible language in those sciences.

So the glory, or halo, round the head is a part of the univerfal language of the eye, defignating a holy perfon; wings on the shoulders denote a good angel; and a tail and hoof denote the figure of an evil demon; to which may be added the cap of liberty and the tiara of popedom. It is to be wished that many other univerfal characters could be introduced into practice, which might either conftitute a more comprehenfive language for painters, or for other arts; as thofe of ciphers and figns have done for arithmetic and algebra, and crotchets for mufic, and the alphabets for articulate founds; fo a zigzag line made on white paper by a black-lead pencil, which communicates with the furface of the mercury in the barometer, as the paper itself is made conftantly to move laterally by a clock, and daily to descend through the space neceffary, has ingeniously produced a most accurate vifible account of the rife and fall of the mercury in the barometer every hour in

the year,

Mr. Grey's Memoria Technica was defigned as an artificial language to remember numbers, as of the eras, or dates of hiftory. This was done by fubftituting one confonant and one vowel for each figure of the ten ciphers used in arithmetic, and by compofing words of these letters; which words Mr. Grey makes into hexameter verfes, and produces an audible jargon, which is to be committed to memory, and occafionally analyfed into numbers when required. An ingenious French botanift, Monfieur Bergeret, has propofed to apply this idea of Mr. Grey to a botanical nomenclature, by making the name of each plant to confift of letters, which, when analysed, were to fignify the number ofthe clafs, order, genus, and species, with a description alfo of fome particular part of the plant, which was defigned to be both an audible and visible language.

Bishop Wilkins, in his elaborate "Effay towards a Real Character and a Philofophical Language," has endeavoured to produce, with the greateft fimplicity, and accuracy, and concifenefs, an univerfal language both to be written and spoken, for the purpose of the communication of all our ideas with greater exactness and lefs labour than is done in common languages, as they are now fpoken and written. But we have to lament that the progress of general science is yet too limited both for his purpose, and for that even of a nomenclature for botany; and that the fcience of grammar, and even the number and manner of the pronunciation of the letters of the alphabet,