Obrazy na stronie

to ve

eren to fourteen ears; a thing almost incredible. The owner of the land seeing his ground fo miserable trodden by the horse and soldiers after the confia, intended to resow it, as believing all his former labour loft ; but, being diffuaded from his purpose, (perhaps to make the experiment) it happened as you, have heard *

• Urine, for being highly spirituous and sharp, had need be well corrected ; and then, being mingled with other compofts to allay its acrimonioas falc, it hardly has its equal.

· Hair, horn-Shavings, bones, skins, leather, &c. are deeply to be buried, and so as not to touch, but lie about the roots : these, with rags, coarse wool, and pitch-marks, improve the earth, as being full of volatile falts, drawing and retaining the dews. Fish is likewise spread to great advantage of grounds, where it is to be had in plenty; and for being quickly consumed, may sooneft be applied t. We come now getables

• The marc and preslings of the grape make a good compost, and so do lees of wine mingled with mould. This is of fingular comfort to the roots of orange trees and case-plants; and if you fift a little brick duft with it, and bury it near the roots of rosemary, the plant will thrive wonderfully: it may be a laudable compost for moist grounds, where that vegetable grows fo unwillingly.

• The leaves of trees are profitable for their own fruit, and natural, being well rotted, and not mufty: the peach leaf, hurtful to cattle, is excellent for the tree from which it falls; and the walnut leaf, noxious to the grass, is helpful to the tree.

• Duck-weed, the nime and spongy ouze of stagnant wa. ters, mixed with proper mould, make a kind bed for aquarics.

• Saw dust, rotten-wood, found in the hollow of decayed trees, under the stacks, and where trees grow thick together, as in great and old woods, but especially that which is taken out of an inveterate willow-tree, is preferable to any other for the raising of seedlings of choice plants, mixed as it should be with a little loam, lime rubbish, and mould, as we have taught.

« • Blood, mixed with saw. dust, makes a very good hand-dressing to be sown upon wheat in the spring. It equals foot, and does not come to half the price.'

• ¢ In all towns upon the sea-coast, the refuse of filh may be obtained upon moderate terms. It is matter of surprize that this hint of our excellent author, given in the year 1675, Mhould have operated 10 little that at this iime (1778) the use of refuse filh is hardly known. The sea, with generous bounty, throws at the feet of the husbandman her richest treasures, and invites him to par. take with freedom ; but he, dull mortal! instead of embracing the proffered riches, drives his team to some diftant town to pure chase, at a bigh rate, what the watery element offers without a price." K 3


This and the rest being well ventilated, is of great effect te loosen apd mellow ground, as tenacious of moisture.

• Wood-alhes, rich and impregnate with salts, are fit for wet ground without mixture, and in pasture excellent, not fifted on

over thick.'

Dr. A. Hunter, to whom the public is indebted for the re. publication of Mr. Evelyn's admired treatise, has enriched it with many pertinent and useful notes.

I 2mo,

Anatomical Dialogues ; or, a Breviary of Anatomy. Wherein all

the Parts of the Human Body are concisely and accurately described, and their Ufes explained; by which the Young Practitioner may'attain a right Merbod of treating Difeases, as far as it depends on Anatomy. Chiefly compiled for the Use of the Young Gentlemen in the Navy or Army.

35. Boards. Robinson. Confidering the unattractive nature of anatomical systems,

they doubtless stand in need of every circumstance that can recommend them to the attention of the medical student. The form of dialogue, therefore, by treating those subjects in a new, and consequently a more interesting manner, may prove particularly useful, especially, when, at the same time, the science is with judgment abridged. These advantages appear to be conspicuous in the volume before us, which is well cal. culated for facilitating the study of anatomy, as well as for af, sifting the memory, when any sudden occasion may call for such a recourse.

As our medical readers will probably not be displeased to see a specimen, we fhall present them with the dialogue con. cerning the eye.

Q. What are the parts of the eye not yet described ?

• A. The bony focket, muscles, cartilages, and ligaments of the external parts of the eye are already spoken of in dialogue the first. The internal parts not yet mentioned are the glandu, læ sebaceæ, caruncula lachrymalis, glandulæ lachrymalis, puncta lachrymalia, orbit; the coats or tunics, viz, tunica albuginea, adnata, or conjunctiva ; tunica sclerotica; tunica cornea ; 19. nica choroides ; tunica uvea, (which contains the iris and pupilla) to which may be added the retina. The humours of the eye, viz. the aqueous, vitreous, and crystalline, to which may be added the extreme thin and fine vascular membrane called tonica arachnoides, and the vessels and nerves of the eye.

Q. What are the glandula sebacee?

A. The glandulæ sebaceæ are liquated in the interior furs face of the eye-lids : they serve for the secretion of an oleaginous Auid, which is of great use in preventing the attrition of the eye-lids, from their continual motion, Q. What is the caruncula lachrymalis?

! A. The

[ocr errors]

* A. The caruncula lachrymalis is a little eminence fituated in the larger angle, or canthus major of the eye, serving to direct the tears to the puncta lachrymalia, and, according to some anatomists, they help to keep them open when the eyes are shut.

Q. What is the glandula lachrymalis ? A. The glandula lachrymalis is feated in the upper and outer part of the orbits, with its excretory duets under the upper eye. {id. This gland separates the matter of the tears, which, by the continual motion of this lid, furnishes at all times water enough to wash of dirt, and to keep the external surface of the eye moist, without which the cornea would dry and wrinkle by the continual action of the external air. As the tears fall off the cornea, they are stopped by the edge of the under eye-lid, along which they ran till they fall into the pancta lachrymalia.

Q. What are the pun&ta lachrymalia ? • A. The puncta lachrymalia are two small holes in the inner corner, or great canthus of the eye, one in each eye-lid ; they are situated at the extremities of the tarsi or cartilages, and lead to a small membranous bag or lachrymal fac, which is seated in this corner upon the os lachrymale; from the bottom of which there goes a fmall pipe or nasal canal, which pierces this bone in the nose opening under the upper lamina of the os spongiofum. It moistens the inner membrane of the nostrils, by the fuperfluous humour of the lachrymal gland. Sometimes the acrimony of this humour causes sneezing, which we may hinder by prefsing the angle of the eye, and so ftop its running. Be. tween these two pun&ta there is a caruncle (as above mentioned) that serves to keep the holes open when the eyes are lut. .Q. What is the orbit of the eye?

A. The orbit of the eye is that cavity in which the eye is contained, and is in all the vacant places filled with loose fat, which is a proper medium for the eye to reft in, and serves as a focket for its motion. The proper parts of the eye, which form its globe, eye-ball, or bulb, are its coats or tunics, the hy. mours, and the vessels.

Q. What is the tonica albuginea ? * A. The tunica albuginea, adnata, or conjun&iva, is the first membrane or coat of the eye-ball ; it is a smooth membrane which covers so much of the eye, as is called the white, and being reflected all round, lines the two eye-lids. Being thus returned from the eye to the inside of the eye-lids, it effečtually hinders any extraneous bodies from getting behind the eye into the orbit, and smooths the parts it covers, which makes the friction less between the eye and the eye-lids. It is full of small veins and arteries, which appear tig in an opthalmia or inflam. mation of the eyes,

Q. What is the tunica sclerotica ? • A. The tunica sclerotica is a thick, hard, and smooth coat, extended from the cornea to the optic nerve ; it is opake behind, but transparent before, where it makes the third coat called cor

K 4




Both together make one firm case of a proper form for the use of the other coats and humours.

Q. What is the cornea ? • A. The cornea, so called from its substance resembling the horn of a lanthorn, is convex, transparent, and composed of various laminæ, which are nourished by many blood-vesiels, so fine as not even to hinder the smallest rays of light from enter. ing the eye. The cornea is situated in the fore-part of the eye, surrounded by the sclerotica and albuginea ; it has a moft exquifite sense, to the end that the tears, upon the least pain, may be squeezed out of the lachrymal gland, to walh off any filth, which, by sticking to the cornea, might render it opake or dim.

Q. What is the tunica choroides? • A. The tunica choroides is the fourth coat of the eye, and is so named, on account of the multitude of blood-veffels resembling the chorion ; it lies immediately under the sclerotica, and is much thinner than it, being a membrane of little firmness. It is blackih, or of a dulky brown colour, more or less inclin: ing to red. This membrane, or coat, has a great number of blood-vefsels which come from the sclerotica. It is open, or has a hole before, for the passage of the rays of light, called pupil, la; the part of this coat, which makes the circumference of the hole, and lies upon the side of the crystalline humour, is the uvea.

Q. What is the uvea, you mention? *A. The uvea is the fifth coat, and is only a white circle round the back fide of the choroides near the cornea, as has been said. In this coat we observe, first the iris, which is a cir. cular variously coloured part, being the anterior surface of the uvea, which surrounds the pupil; it is called the iris, because in different persons it is of different colours ; hence the denomi. nation of grey, blue, brown, hasel, black eyes, &c. The iris is entirely vascular, from which arises the variety of colours in the human eyes. Secondly, the pupil, or foramen, which is round in the human eye, nearly in the middle of the iris, and is capable of dilatation and contraction. Through this aperture, the rays of light pass to the crystalline, in order to be painted on the retina, and cause vision. Thirdly, its pofterior surface, which is black, and in which, when this blackness is cleared away, there appears the sphincter of the pupil, formed of circular fibres for contraction, the ciliary fibres or processes, for the dilatation of the pupil; the ciliary ligament for the mo. tion of the vitreous and crystalline humours; the arterial and venal circles, from the vessels, are in a wonderful manner distributed over the 'uvea; the choroides; the ligamentum ciliare; and the vitreous and crystalline humours; the ductus nigri, fo called from their black colour, placed between the processes and the ligamentum ciliare; the space between the ovea and the cornea, called the anterior camera of the eye ; and that between the uvea and crystalline, called its posterior camera, which is either much smaller, or entirely wanting.

.Q. What

[ocr errors]

Q. What is the retira? • A. The retina is a membrane which may be called the sixth tunic or coat; it lies immediately under the tunica choroides, and is a very delicate, tender, and as it were, mucous coat of the eye, or more properly, it is only an expansion of the optic nerve at the bottom of the eye. It is the great organ of vision, and called retina because it somewhat resembles a ner: rays of light ftriking upon this membrane, the sensation is conveyed by the optic nerves to the common sensorium, the brain.

Q. What is the aqueous humour of the eye ?

A. The aqueous humour lies in the fore part of the globe, immediately under the cornea : this humour is thin and liquid, of a fpirituous nature, for it will not freeze in the greatest tsoft. This evinces the necessity of a continual supply of this humour; which is manifest it hath, because if the cornea be pricked, and this humour squeezed out, it will be again restored in ten or twelve hours : this aqueous humour lying foremoít, seems chief. dy of use to prevent the crystalline from being easily bruised by rubbing, or a blow; and perhaps it serves for the crystalline humour to move forward in, while we view near objects, and backward for remoter objects.

Q. What is the crystalline humour ? * A. The crystalline humour is the second, and distinctly contained in a very fine coat or membrane called aranea or arachəoides, and is suspended by means of the ciliary ligament, between the aqueous and vitreous humour, immediately behind the pupil; in this place it hangs free, and is moveable by means of the ligament just mentioned. It is composed of a multitude of lamellæ like the coats of an onion ; and therefore also pellucid and vascular. There is also a small quantity of the aqueous humour contained within or under its coat. The crystalline being a thick, compact humour, in form of a fattish convex lens, situated in the middle of the eye, ferves to make chat refraction of the rays of light necessary to make them meet in the retina, and form an image thereon, whereby vision may be performed.

Q. What is the vitreous humour ? • A. The vitreous, or glasfy humour, is the third humour of the eye, so called from its resemblance to glass in fusion, being like a fine clear jelly in appearance; it is thicker than the aque. ous, but thinner than the cryftalline ; and is in greater abun. dance than the other two, It lies behind the crystalline, and fills up the greatest part of the eye ; its forefide is concave for the cryftalline humour to lodge in, and its back-lide being convex, the tunica retina is spread over it; it serves as a medium to keep the crystalline humour and the retina at a due distance.

What are the blood-veisels and nerves of the eye: "A. The eye is furnished in a most wonderful manner with nerves and blood vessels in all its parts. The blood. veffels of the eye are branches of the carotids and jugulars,


« PoprzedniaDalej »