9 abscissæ referred to the line CC as the general line of the ordinates represent the deviations of the temperature of any point g for any time p taken on that line. The ordinates C B, B G, GE, EC make up the mean temperature line of 24 hours, or 1440 minutes. One degree of temperature in the projection is convertible into 60 minutes, being equal to an hour of time. We may hence readily obtain the abscissæ in terms of the ordinates or reciprocally, by merely converting degrees into time. It is not therefore difficult from the known equation to the parabola, or y2 = 4ax, to calculate the temperature of any point q which should arise at any point of time p, on the supposition that the four curvilinear branches are semi-parabolas, and so compare the observed temperatures with those of calculation. For this purpose the following formulæ may be employed, which are easily arrived at. = Let T the temp. for any point q at any time p; m = the min. = 49°; M = max. = 58°; y = any ordinate taken on the line C C variable in time. Then for the morning branch AB we have T = m + for the noon branch B D... . . . T=M AC x y (CB)2 PG x y2. (BG)2 ; for the afternoon branch DE ..... T= M DG x y2; (G E)2 for the night branch EA. . . . . . . . . T = m + ........ By these formulæ the curvilinear branches A B, AC x y2 (CE) BD, of the * These formulæ, as shown by Sir David Brewster in his investigation of the Leith observations, are deducible in the following way: Taking one of the branches, as BD, Plate X. we have by the property of the parabola G Da (BG). If therefore q be any point of temperature at any given point of time p, then in drawing p q and n q DG: Dn:: (GB): (n q), hence Dn = 2: : (y)2 GD. y2 (GB)2 Now it is to be observed that G D is the deviation of the maximum = M from the line of mean temp. =, and pq=Gn= (GD-n D) the deviation at time p; hence temp. at point D= ( +GD) = M, and for any other point q at any other time p we have T = (+ GD) - Dn. Substituting therefore the values of (+GD) and D n in this equation, we get for the branch BD, T=M GD.y2 (G B) By a similar process we arrive at the formulæ for the branches below the line of mean temperature CC in substituting m for M, the value of m being m = (μ — A C). mean annual daily curve have been calculated, on the supposition that they are semi-parabolas of the following dimensions Morning branch A B.. Ordinate BC= 192' = 3°.2 Absciss. A C = 234' = 3°.9 = = : The results are given in the following Table, which contains the calculated and observed temperature for each hour, together with the differences. TABLE XVI.-Showing the mean annual Hourly Temperatures for 1833 and 1834 at Plymouth, as observed and calculated on the supposition that they may be represented by Parabolic Abscissæ. We observe in this Table that the approach of the branch E A at night to a semi-parabola is very close, the differences not being in any case two tenths of a degree of Fahrenheit. In the morning branch A B and noon branch BD the differences are somewhat more considerable, but still not so great as to destroy the approximation. In the afternoon branch, however, D E the deviations amount in one instance to more than eight tenths of a degree, and are too considerable to warrant this branch being taken as a semi-parabola. Whether more extended observations will tend to reconcile these differences is yet to be seen. It is not unworthy of remark that although in the results of Dr. Brewster's inquiries the deviations did not in any case exceed a quarter of a degree of Fahrenheit, yet the differences, as at Plymouth, were greatest in the afternoon branch. I hope at no distant period to present to the Association the results of the hourly observations for five complete years, after which it is intended that the register shall close. This Report, at present necessarily limited, may then probably admit of further extension and correction, so as to obtain better approximations than those arising from two years observations only. Plymouth, July 20th, 1835. Report of the Committee on Chemical Notation. DR. TURNER, the Chairman of the Committee appointed to take into consideration the adoption of an uniform system of chemical notation, made a report to the following effect: 1st. That the majority of the Committee concur in approving of the employment of that system of notation which is already in general use on the Continent, though there exist among them some differences of opinion on points of detail. 2ndly. That they think it desirable not to deviate in the manner of notation from algebraic usage except so far as convenience requires. 3rdly. That they are of opinion that it would save much confusion if every chemist would always state explicitly the exact quantities which he intends to represent by his symbols. Dr. Dalton stated to the Chemical Section his reasons for preferring the symbols which he had himself used from the commencement of the atomic theory in 1803 to the Berzelian system of notation subsequently introduced. In his opinion regard must be had to the arrangement and equilibrium of the atoms (especially elastic atoms) in every compound atom, as well as to their number and weights. A system either of arrangements without weights, or of weights without arrangements, he considered only half of what it should be. On the Infraorbital Cavities in Deers and Antelopes, called Larmiers by the older French Naturalists. By A. JACOB, M.D., Professor of Anatomy to the Royal College of Surgeons in Ireland. IN In compliance with the recommendation of the Committee of the Zoological Section of the Association made at the meeting in Cambridge in 1833, I have availed myself of such opportunities as have been afforded me for investigating the nature, structure, and uses of these remarkable parts. To those altogether unacquainted with the subject, it is necessary to state that they consist of two oval depressions about an inch and a half long, half an inch wide, and more than three quarters of an inch deep, in the majority of instances; situated on the side of the face, and so near to the inner angle of the eye that they create a very reasonable suspicion that they are connected with that organ, and hence the term larmier applied to them. The bottom of the depression is in most cases naked, but in some it is covered with the hair; consequently it is composed of the skin formed into an open sac accommodated in a corresponding depression in the bones of the face. In many animals provided with this organ a gutter, formed by folds of skin, leads so directly to it from the surface of the eye, that the passage of the tears from the one place to the other appears inevitable, while in others this communication is so imperfect that a doubt is at once raised as to its destination to such a purpose. If the part in question be not a cavity, as suggested by some, in which the overflowing secretions from the surface of the eye are disposed of by evaporation, another reason for its existence must be assigned. The arguments which may be urged against the supposition that it is destined to receive the tears are, first, that it exists in the antelopes and deers only, and is even absent or merely rudimental in many of these, while in animals said to be destitute of the usual canals for carrying off the tears to the nose, as the elephant and hippopotamus, it is absent; secondly, that the solid concretion generally found in it is not composed of such ingredients as the tears and other secretions from the surface of the eye should afford. If the conclusion that these are cavities for the reception of tears be discarded, their identity of nature and character with the numerous provisions for the secretion of peculiar or odoriferous materials suggests itself. In many instances, especially |