some further observations on plants, and the analogy between them and the animal creation.

449. The substance of vegetables is composed of sulphur, volatile salt, water, earth, and air.

450. Water and air enter by the roots, and ascend in the respective tubes, the water forming the sap; and nature has taken care to cover the roots with a very fine thick strainer, that nothing can be admitted into them but what can readily be carried off by perspiration, vegetables having no other provision for discharging their recrement. 451. The elastic aerial fluids distend each ductile part, and by enlivening and invigorating the sap, and mixing with the other principles, they, by heat and motion, assimilate into the nourishment of the respective parts. While in this nutritive state, by the gradual cohesion of the constituent particles, they are at length formed into a firmly compacted body.

452. The sap rises all winter, but in a smaller degree than in the summer. And the perspiring matter of trees is rather actuated by warmth, and so exhaled, than protruded by the sap upwards.

453. The air enters into the vegetable, not only by the roots, but also by the trunk and leaves, especially at night, when they are changed from an expiring to an imbibing state. Part of the nourishment of vegetables arises also from the leaves plentifully imbibing dews and rain, which contain salt, sulphur, &c. the air being impregnated with these substances.

454. Leaves are also instrumental in drawing nourishment from the roots, and furnishing the young shoots with nutriment. They also contain the main excretory ducts, and separate and carry off the redundant watery fluid, which by being long detained, would turn rancid, and be prejudicial to the plant; thus leaving the more nutritive parts to coalesce.

455. The use of leaves, which are placed just where the fruit joins

to the tree, is to bring nourishment to the fruit; accordingly, we find that the leaves, next adjoining to blossoms, are, in the spring, very much expanded, when the other leaves on barren shoots are but be ginning to shoot: so provident is nature in making timely provision for nourishing the embryo fruit.... The pedals of leaf-stalks are also placed where nourishment is wanted to produce leaves, shoots, and fruit; and some such thin leafy expansion, is so necessary for this purpose, that nature provides small thin expansions, which may be cal led primary leaves, that serve to protect and draw nourishment to the young shoot and leaf-buds be fore the leaf itself is expanded.

456. A dilating spongy substance, by equally expanding itself every way, would not produce a long slender shoot, but rather a globose one; to prevent which, nature has provided several diaphragms, besides those at each knot, which are placed at small distances across the pith, thereby preventing its too great lateral dilatation. We may also observe, by the bye, that nature makes use of the same artifice in the growth of the feathers of birds.

457. The great quantity of moisture perspired by the branches of trees, during the cold winter season, shows the reason why a long series of cold north-easterly winds, blasts the blossoms and tender fruit, the moisture exhaling faster than it can be supplied by the trees. Hence the use of snow in covering the leafy spires of corn, in such weather.

458. The proof we have of the utility of leaves in drawing up the sap, and the care nature takes in furnishing the twigs with plenty of them, principally near the fruit, may instruct us, on one hand, not to be too lavish in pruning them off, and to be careful to leave some on the branch beyond the fruit; and on the other hand, to be careful to cut off all superfluous shoots, as they draw away a great quantity of of nourishment. Thus far Mr. HALES.

459. When a seed is sown in a reversed position, the young root turns downwards and enters the earth, and the stem bends upwards into the air. Confine a stem to an inclined position, and its extremity will soon assume a perpendicular position. Turn a branch so that the under side of the leaves may be upward, and the leaves will soon regain their natural positions..... Many leaves follow the motion of the sun; in the morning their superior surfaces are towards the east; at noon, toward the south; at evening, toward the west; and during the night, or in rainy weather, these leaves are horizontal, with their inferior surfaces toward the earth. What is called the sleep of plants, affords another instance of vegetable motion. The leaves of many plants fold up in the night, and open again in the day. And it is worthy of remark, that they all dispose themselves so as to give the best protection to the young stems, flowers, buds, or fruit. Many flowers have also the power of moving. During the night, many of them are inclosed in their calixes. Some flowers, when asleep, hang their mouths to wards the earth, to prevent the noxious effects of rain or dew. If a vessel of water be set within six inches of a growing cucumber, the direction of its branches will soon tend towards the water. When a pole is placed at a considerable distance from an unsupported vine, the branches will soon tend towards the pole, and twist about it. The sensitive plant possesses the faculty of motion in a remarkable degree; the slightest touch makes its leaves suddenly shrink, and, together with the branch, bend towards the earth. These circumstances tend to prove, that plants are endowed with irritability.

460. The structure of plants, like that of animals, consists of a series of vessels disposed in a regular order. The economy and functions of vegetables, as well as those of animals, are the results of a vascular téxture. The pith, or medul

lary substance of plants, resembles the spinal marrow of animals; and when the texture of either is destroyed, the plant or animal dies. The round bones of animals consist of concentric strata, which are easily to be separated: and the wood of plants consists of concentric layers of hardened vessels, which separate when macerated in water. A trec acquires an additional ring every year, and thus its age may be pretty accurately obtained. Animals and vegetables gradually expand from an embryo state, and sooner or later arrive at perfection. Some parts of animal bodies partake of the nature of vegetables. Thus, the hair, the nails, the beak, and the horn, are a species of vegetables, as appears from their total insensibility. There is a striking analogy between the eggs of animals and the seeds of plants. When placed in proper situations, they both produce young, similar to their parents. There is also a great similarity in the structure and uses of their respective organs. Many animals have seasons peculiar to their respective kinds. Some animals produce in the spring; others in autumn; and others in winter. And particular vegetables also have their respective seasons. And thus nature has wisely ordained, that the earth should always be covered with plants. Hence, by taking a general survey of the vegetable and animal kingdoms, it appears, that nature in their formation has operated upon one and the same great principle and model.

ON MEASURES.

461. In settling the measures of different nations in respect to their relative values; we have followed what we judged to be the best authorities, and where we could procure different measures to which we could attach equal credit for accuracy, we have taken the mean; we trust therefore that the following tables will exhibit the values of an

63360 21120

462. The Scotch Elwand is divided into 37 inches, and is found equal to 37 English inches; therefore a Scotch inch and foot are to the English, as 185 to 180. Itinerary measure is the same in Scotland as in England. The length of the chain is 4 poles, or 22 yards; and 80 chains make a mile. The old Scotch computed miles were about 1 English miles.

463. The English Ell is 14 yard and is used in measuring linens imported from Germany and the low countries.

464. An English fathom is to a French toise, as 1000 to 1065,75. The toise contains 6 feet; the foot contains 12 inches; and the inch contains 12 lines. As the fathom and toise contain the same number of feet, an English foot is to a French foot, as 1000 to 1065,75.

465. Landis measured by a chain, called Gunter's chain, from the inventor; its length is 4 poles 22 yards 66 feet. It consists of 100 equal links, each of which is therefore 7,92 inches. Land is estimated in acres, roods and perches. An acre contains 10 square chains; therefore 10 chains in length, and 1 in breadth, make an acre, the form being supposed that of a rectangled parallelogram. A rood is one-fourth of an acre; and a perch is the fortieth part of a rood, or it is a square pole. Hence, an acre contains 10X 1-10 square chains=40×4=160 square poles = 220 x 22 = 4840 square yards=1000×100=100000 square links. Also, 625 square links-1 square pole, or a perch; 40 perches=1 rood; 4 roods=1 acre. A square mile contains 640 acres. A hide of land, mentioned in the earlier part of our history, contained about 100 acres.

466. In Scotland, the measure of the land is regulated by the ell: 36

square ells=1 fall; 40 falls=1rood; 4 roods=1 acre. The Scotch acre is to the English, as 10000 to 7869. The length of the chain used in Scotland for measuring land, is 24 ells=72 feet.

467. In solid measure, 1728 inches 1 foot; and 46656 inches =27 feet=1 yard.

468. In wine measure, 287 solid inches=1 pint; and 231 inches=8 pints=1 gallon.

469. In ale measure, 351 solid inches=1 pint; and 282 inches=8 pints=1 gallon.

470. In dry measure, 333 solid inches-1 pint; and 268 inches⇒ 8 pints=1 gallon.

471. In Winchester corn mea

sure, 34 solid inches=1 pint; and 272 inches-8 pints=1 gallon; also, 8 gallons=i bushel.

472. The Scotch quart contains 210 solid inches.

473. Forty feet of hewn, and fifty of unhewn timber, make a load.

Of these measures, the digit, inch, palm, foot, cubit, and pace, were in use amongst the architects; the foot, pace, stadium and mile, amongst the geographers.

474. Of the ancient Roman superficial measure, the jugerum, or acre, was the unit; and this, like the As, Libra, or any other integer, they divided as follows, the jugerum being a unit answering to the As, and containing in Roman and English square measure.