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12, 11 57 47 13, 9 47 55 The nucleus admitted of very precise observations; indeed it is a curious fact that it would be quite possible by means of proper comparisons with neighbouring stars, to obtain the differences of terrestrial longitudes of the principal points at which it was observed, with a degree of precision only surpassed by the more refined methods known in astronomy.

The near approach of the present comet to the earth and the sharply defined point of its nucleus, illustrates the practicability of a method of determining the solar parallax with perhaps greater exactness than can be attained by any other means. Many comets have stellar points for their nuclei, visible in the larger telescopes, which admit of as accurate comparisons with neighbouring stars as is practicable in measurements among the stars themselves. Many such have appeared within the last fifteen years. Suppose such a comet to be suitably placed so as to be observed simultaneously in different quarters of the globe, when at a distance from the earth of less than one-twentieth of the sun's distance. Under favorable circumstances it would not be hazarding too much to say, that in the course of its apparition the probable error of the solar parallax could be reduced within smaller limits than is possible by means of transits of Venus or of any other method. Such an opportunity might possibly afford an improved value of the mass of the earth.

From the above elements, the diameter of the nucleus may be variously estimated at from one hundred and fifty to three or four hundred miles. On July 2d the breadth of the head at the nucleus was 156,000 miles, the height of the inner envelope 11,500 miles, and the length of the tail about 15,000,000 miles.

The comet was seen between one and two o'clock on Sunday morning, June 30th, by Dr. Brunnow, at the Observatory of Ann

Arbor. This is the earliest authentic account of its visibility which has come to my notice. The head could not have been seen on Friday evening, although observations to that effect have been reported. The extremity of the tail, however, must have been within view for some time previous, though too faint to attract notice.

The reports current of the identity of the comet with those of 1264 and 1556 are without any foundation.

ARTICLE XXI.-What to observe in Canadian Lichens. By W. LAUDER LINDSAY, M.D., F.L.S., Neill Medallist of the Royal Society of Edinburgh, and Hon. Mem. Bot. Soc. of Canada.

(From Annals of the Botanical Society of Canada.)

An account was given of the importance of Lichens in the phenomena of nature, and of their applications to the wants of man, in affording food, dyes and fodder. Specimens of many of the most valuable dye species were shown, including Roccella tinctoria from Greece; a series of Umbilicaria named by Leighton, in accordance with his Monograph; Sticta pulmonaria and dye prepared from it, from the woods around Kingston; and an interesting collection of Lichens made in the United States by Mr. A. O. Brodie, of the Ceylon Civil Service. The points brought before the Society by Dr. Lindsay were the following:

1. There are no plants so variable in character as the lichens; none in which it is consequently so difficult to decide what are species and what are varieties. In order to a comprehensive knowledge of species, it is necessary to study individuals in every condition of growth and from every possible habitat. Hence the commonest species and varieties become of value-the more so if collected in countries comparatively unexplored botanically, for lichens are no exceptions to the rule that geographical differences are attended by corresponding differences in the characters of the same plants. Every Canadian collector of lichens-however com mon and well known the latter may be may therefore consider himself as contributing towards a more scientific and philosophical, because more comprehensive, knowledge of a very Protean, but interesting, group of plants.

2. If the collector make a point of gathering specimens of every, thing he meets which belongs to the lichen family, he will run a good chance of including some novelties, perhaps new species or varieties. This is extremely probable in a country like Canada,

seeing that it is seldom a miscellaneous collection of lichens is made in any part of Britain at all remote from the largest towns without the discovery of interesting novelties. New species are most likely to be met with among the very minute crustaceous lichens which grow on rocks or trees, and which cannot be properly studied without the aid of the microscope; among species belong ing, for instance, to such genera as Lecidea, Lecanora, Graphis, Opegrapha, Calicium. It is not to be expected that the tyra should make these microscopical examinations or discoveries for himself: he will probably require the assistance of some experienced microscopist or lichenoligost.

3. The applications of lichens to the arts are daily becoming more numerous and important. New dye-lichens are being discovered in India and the East. Among specimens of the latter recently sent me from India, I have found species not hitherto known to be of any practical use. Again recently the probability has been shown, on good grounds, that a lichen-the Lecanora esculenta of Pallas-was the Manna of the Bible.

4. The colorific capability of a lichen, so far as regards a red or purple dye of the nature of orchill or cudbear, may be readily discovered by simply macerating the lichen-chopped into small fragments or pulverised according to the nature of its thallusin a weakish solution of common hartshorn (the quantity not much covering the lichen in a vial of any sort)—that is, the "liquor ammonia" of druggists—allowing the mixture to stand a few days in a warmish part of the house, aud shaking it frequently, so as to expose the mass to the action of the air. Colorific lichens of this class belong chiefly to the genera Roccella, Umbilicaria, Romelia, and Lecanora.

5. The colorific capability of a lichen, so far as regards other colors-chiefly brown and yellow-may be easily ascertained by simply boiling the lichen, chopped or pulverised as before, in a small quantity of water. Colorific lichens of this class belong chiefly to the genera Romelia, Sticta, Cetraria, &c.

6. Whether and how much mucilage or starch a lichen contains may be ascertained by the same means as last mentioned, and allowing the mixture to cool, when it will gelatinise more or less, if it contain much mucilage. Cetraria Islandica and some of the Umbilicariæ are illustrations.

7. Contributions may also be made to our knowledge of the economical applications of lichens by ascertaining whether any

and what species are, or have been, used in Canada by the native Indians to yield food, dyes, &c., noting all the particulars of such

uses.

8. Lichens are very easily collected and transported; they require no sort of preparation; they may be simply allowed to dry in the open air and packed as convenient. Those growing on trees generally require the piece of bark on which they grow to be sliced off with a knife, and those on stones the piece of rock to be broken with a hammer. Both may be wrapped in paper like mineralogical specimens. In all cases the localities and dates of collection should be mentioned, and any futher information as to uses, &c., which may be known to the collector.

The Rev. Principal Leitch, the President, in drawing the proceedings to a close, congratulated the Members on the success of the Meeting, and the wide interest manifested in the Society's proceedings. This meeting differed from those previously held in regard to one circumstance—the presence, of the Lady members. Botanical researches of great value had been carried out by ladies in other countries and all Departments of Scientific knowledge had benefited by their exertions. It was gratifying, therefore, that the ladies of Kingston were not behind in this respect, and he looked forward with interest to the contributions which they would no doubt continue to make to the Society's Meetings, in imitation of the example set by Mrs. Lawson. The President concluded by giving some interesting details regarding the employment afforded by the silk culture in Judæa.

The Society then adjourned.

ARTICLE XXII.—On the Mammals and Birds of the District of Montreal. By ARCHIBALD HALL, M.D., L.R.C.S.E. "When accurate lists of the resident birds in each region, and of the " summer and winter visitors, are obtained, many highly interesting and "unexpected deductions will doubtless be made, and much theoretical reasoning exploded."-Fauna Boreali Americana.

EDITORIAL NOTE.

Richardson and Swainson.

[The following paper is a portion of an extended memoir of 153 MS. pages, prepared by Prof. A. Hall, M.D., for the Natural History Society of Montreal, in 1839. It received the silver medal offered by the Society; but unfortunately for the interests of science and the reputation of the Society, was not printed.

Some years after, its printing was recommended by the Council, but nothing was done. Subsequently it was entrusted to Prof. Cassin of Philadelphia, to be used in the preparation of his work on American birds, in which it is frequently quoted with expressions of high commendation. Dr. Cassin retained the M.S. for some years, and it has only recently been returned by him. Had it been printed when written, it would have been a most important contribution to American Natural History, and would have brought to its author and to the Society a large meed of scientific reputation. Even now, after much of the work involved in its preparation has been done over again, it contains so much that is of interest in Canadian Natural History, that its publication should no longer be delayed.

The portion now presented is the introduction and the account of the mammalia; the birds, which occupy the greater part of the memoir, being reserved for a subsequent opportunity.]

INTRODUCTION.

In submitting the following pages to the Natural History Society of Montreal, a few introductory observations are requisite, as well to explain the object contemplated in the work, as to offer an explanation why the obvious intention of the Society in offering for a subject" the Zoology of the District of Montreal," could not be attained, at least by the author.

With respect to the first, the motto which has been selected for the essay, is amply explanatory, and in reality, little more has been attempted beyond that object. It was rather with this intention, than to enter into competition for a prize, that the author has bestowed his labour. The necessity of attempting to establish the migratorial ranges of the feathered tribes, is acknowledged at the present day, and it has become an important matter of speculation among zoologists; and nothing can advance this end so materially as correct lists of the resident and non-resident birds in various distantly situated localities. With the view of attempting a solution of the problem, this has been carried into effect in several places. Those of the northern, and north-eastern coasts of this continent have received a partial elucidation. Richardson has given us a tolerably correct list of those of the Saskatchewan district. Charles Lucien Buonaparte has furnished a list of those which are resident or visitors in the neighbourhood

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