uniformly fell into this opinion. But as they wanted instruments, their observations had a confined range, were vaguely made, and consequently indeterminate. In their details the seasons are distinguished as very hot, dry, cold, or wet: the summers are described as unusually cold, or oppressive from heat; the winters are characterized by the long or short duration of frost. It was not possible to show the precise degree of any of these. From the want of meteorological records, it is still disputed what changes have taken place in the climate of the British islands. If we were to admit the statements of some of our old historians, who, in pages of flowery eloquence, describe the genial warmth of the British vallies, where even the vine flourished with luxuriance, and produced the richest grapes, it must be allowed that the temperature of this country has been considerably lowered. But an observation has been made by an ingenious naturalist (p. 97 of this Number), from a nearly demonstrable fact, that in some very early period, these regions, the ultima thule of the Romans, were much colder than at present. If in these early periods it had been possible to have kept correct registers of the weather, and such registers had been continued from age to age, they would, it is probable, have afforded data explaining operations of the atmosphere upon animal life, which now remain in obscurity. Let us bear in mind that we possess the means of delivering down to future ages meteorological facts, which may prevent our successors experiencing difficulties with regard to the present which we now feel of the past time.

Of all the diseases which appear to be diffused by the atmospherical mediam, the epidemical catarrh, under the popular term Influenza, has the strongest character, and the widest range. If we could know the exact state of the atmosphere, in all its bearings, of 1510, the earliest recorded instance of this epidemic, and in the subsequent times of its recurrence in 1557, 1580, 1587, 1591, 1675, 1709, 1733, 1743, 1762, 1767, 1775, and 1782, there would be a probability of arriving at some principle explanatory of its cause, and of its connection with or dependence on some state of the air. These observations have been suggested by the preceding statement of Dr. Pole, the correctness of which we cannot doubt; and to its utility we are perfectly alive. As far, however, as these meteorological statements regard the practice of medicine, we will suggest that they would be greatly improved by adding to them a columa, containing a register of the prevailing diseases, or such trains of morbid actions as constitute epidemics, in each year or subdivision of

the year.
(No. 144.)

To the naturalist, as well as the physician, it would render these registers more distinct and perspicuous, if the particular kinds of instruments employed were described. ED.

Theoretical Suggestions for the Improvement of Practical Surgery.

(Phil. Magazine.)

1st IN that part of the operation of amputation when the bone is to be sawed through, it appears that a steady support to the bone would materially facilitate and secure the correct action of the saw In the present mode, when the only means of steadying the bone and resistance to the action of the saw is made by the grasp and manual force of frequently agitated assistants, the difficulty of dividing the bone, without splintering and ruggedness, is very considerable. Might not a perpendicular prop from the floor, with a semicircular hollow to receive the bone, be of great effect in rendering it steady? When a retractor is used, might not such prop form part of that instrument? Carpenters, when

they saw timber, always take care to make arpenters, when

it

to the application of the saw; why should not the same mode be used when sawing the bones of the arm or leg? The soft parts could not be injured by such a method; as by the present mode of amputation, by double incision, a considerable length of bone, is bared before the saw is used, and why might not the proposed support be applied to that part

2d. In the operation of trepaning the skull, when the scalp is sufficiently removed, it is essential to remove just so much of the pericranium and no more, as the head of the trephine will include; because the cranium, when denuded of its pericranium, will, like other bones denuded of their periosteum,' grow carious. This part of the operation is now gencrally performed by an instrument called a raspatory, or by scraping the skull with a small scalpel. Would not this be performed much more complete by having a head adjusted to the trephine handle, precisely the dimensions of the Serrated head, and which head would have a circular cutting edge, with a species of concave plane or scraper within it? One turn of such an instrument, which any person could easily contrive, but which is difficult to describe by words, would completely remove the exact portion of pericranium and no

more.

3d. Were surgeons to make themselves acquainted with the implements used in different mechanical professions, it is pos

sible some valuable additions might be made to the present instruments of surgery. They should likewise observe with a professional eye, the various mechanical improvements which are daily taking place. Might not the circular saw be introduced in some operations? Small circular saws, cutters, or wheels with toothed edges of different sizes and thickness, might perhaps be used with effect in insulating and removing the depressed angular pieces of bone which occur in fractures of the skull. When the trephine is admissible, a circular cutter applied to the edge of the fracture might, if used with proper precaution, cut away the bone with safety, and make a space sufficient to admit the elevator. Such a cutter might be turned by the hand, as great velocity would be dangerous. A method could easily be contrived to apply such an instrument with the requisite steadiness to the part

4th. The centre point of the trephine necessarily protrudes beyond its teeth; in consequence of which, when the inexperienced operator neglects too long to remove it, the most. serious effects are sure to follow. Might not this be easily prevented by having a shoulder, as mechanics term it, to surround the point, just so far down from the extremity of the point, as to permit the saw to fix itself, and no more? 5th. Would not a contrivance be useful, in trepanning the skull, to fix the head in the most favourable posture? 6th. The best shape for the points of one description of. piercing instruments has never yet been exactly ascertained ; and it is certainly a question of considerable importance. ac Those piercing struments' are meant, where breadth is requisite immediately on insertion; for, as to common needles, and other small instruments" merely for piercing, it is evident the it the more acute their points are made, the better. In some instruments, however, where a point is merely · for their abortion, "when that point is much prolonged beyond the eficient part of the instrument, it be, es injurions: What point will suit such an instrument best? Is it well ascertained that the drill or shear point is the most advantageous? If the point formed an acute angle,, sloped to one side, would it not answer as well? What is the proper angle for such a point? Mechlinics pierce brass, copper, and steel with drills of different strapes: May not there be an appropriate point for piercing animal membranes? The French discovered by experiments (fatal experiments!) that the descending blade' of the guillotine cut. best when sloped to a certain angle. However confident may be our opinion, experiment should always be had recourse to, when possible; and in satisfying the present doubts, it is very possible. An apparatus might easily be

comes

U 2

contrived

contrived for the purpose. All that is requisite is, a piece of brass, about four inches long and two inches square, supported by two or more feet, and perforated longitudinally, to admit a thick steel pin, which pin is to be fitted to the perforation in the brass, so as to move very freely, and to exceed the brass about two inches or more in length. On the upper end of this pin, a small flat piece of brass should be fixed, capable of holding weights; and in the lower end, a hole made, into which the different shaped points on which we are desirous to make experiments are to be fixed, similarly to the shifting feet of common compasses. Imme-> diately below this pin should be placed a species of dram, consisting of a small box, with bladder or other elastic substance stretched over it to imitate the animal tunics.

Now it

is evident, that by placing different weights on the upper end of the pin, until the point experimentinguon pierce the stretched bladder, may be exactly appreciated the comparative advantage of the different kinds of point, ne nas

7th. The operation of couching frequently fails, from the cataract or opake crystalline lens being of a soft consistency; which the couching needle, instead of depressing, passes through and divides. If the broad part, which is frequently used in depression, were made concave so as to fit the convex edge of the lens, might it not in some degree remedy this evil?

8th. Considering that the majority of calculi in the bladder are more or less spherical, it appears that the forceps now used in lithotomy is not of the most advantageous construction. By each side of the beak of the usual forceps being concave, with an oval hole at the bottom of the concavity, similar to the forceps once used in extracting polypi, the ledges of which hole, and the sides of the concavity, might have teeth, Would it not be more likely to lay hold of even an irregularly spherical calculus than the forceps at present used, with toothed beaks and flat sides? and which seems better contrived for crushing a soft calculus to pieces, than for holding it fast and withdrawing it whole.

9th. Another kind of forceps for extracting the stone may be suggested. Suppose a forceps with the beaks. formed of two narrow elliptical rims, jointed so as in some degree, by the pressure upon a calculus, to conform them- ́ ́ selves to its size. To the edges of these rims attach a picce of linen or leather, forming to each beak a small purse or, sack When these forceps should be closed upon a calculus in the least spherical, the steel rims would extend to let it pass, and it would then be completely surrounded. The advantages of these forceps would be, that the calculus

could

could not escape ; and the bulk to be withdrawn through the wound, would be very little more than the exact bulk of the calculus.

ས རྩ་ན་

1:41

A

On the Barometer. By RICHARD WALKER, Esq.'"
(Continued from p. 52 of our last.)'
(Phil. Mag.)

warm temperature of the air, at any degree of density of the atmosphere, will retain a greater portion of water in a state of chemical combination, than a cold temperature of the air at a similar degree of density of the atmosphere. Hence we may account for the almost constant day state of the lower stratum of the atmosphere during the SUMMER SEA SON, and the almost constant moist state of the lower stratum of the atmosphere during the WINTER SEASON; the air; howe ever, being sometimes sufficiently dense, as in the clear weather which accompanies a freezing atmosphere, to retain the water in a state of chemical combination, gotivithstanding the diminution of temperaturę. L esbivib bas duor The same circumstance accounts likewise for the different states, with respect to moisture and dryness, afl the middle seasons, viz. SPRING AND AUTUMN, accordingly as these 3 participate in their asture more or less of either of the former seasons; observing that, cæteris panibus, there is more rain! aud misty weather during AUTUMN than SPRING,in couse quence of the greater quantity of water which has been raised into the atmosphere during the SUMMER than the WINTERS SEASON 2 Omizo ai bozu oɔno eqpoio? out o, talimi e

n

All the circumstances I have Jl obcasion for mention, de pending upon the greater or less density, and the higher and· lower degrees of temperature of the atmosphere; (ares exem- 9 plified by the two following fandiliarlexperiments: 520 tu.29-7 In the first instance, by means of pubping out of a glass receiver (containing air apparently dry andfectly trans parent) a certain portion of the air it contains, when the airbeing tarefied deposits a certain portion of the water it origi nally contained in chemical combination in a cloudy vapour,, which, upon re-admission of the air, is re-absorbed ; and in the second instance, by abstracting heat from acgkiss vessel containing atmospherical air, and again restoring the heat. The latter direuistance is likewise instanced, nadrally, by what commonly happens in the course of a hot summer's day, particularly when the ground has become very moist by previous rain; the vapour ascending visibly in the morning,

1