ticity of its vegetable membrane, and frozen fruit becomes, as we know, very much shrivelled. Each cell, therefore, acts like a bottle of frozen water, only there is no bursting, because the membrane is extensible.'

"But when plants, easily killed by cold, are exposed to so low a temperature as that just described, it is to be feared that phænomena actually connected with the destruction of vegetable life may be intermixed with others, which merely indicate the physical effects of cold upon vegetable matter already dead. For the purpose of judging how far this conjecture is well founded, I have carefully examined the post mortem appearances of several plants killed by exposure to a temperature artificially reduced only to from 28° to 30° Fahrenheit. These observations, while they have confirmed the general accuracy of Professor Morren's statements, have led to other conclusions which also appear important.

"I could not find the vesicles of cellular tissue separable from each other, even in the most succulent species submitted to experiment, and I conclude that this circumstance, to which Professor Morren attaches importance, and to which M. Payen ascribes the difficulty of extracting starch from frozen potatoes, is not so much connected with the destruction of vegetable life as a result produced upon the tissue by a great intensity of cold. I did, however, find it lacerated in several cases, as if by the distension of the fluid it had contained. In a Stapelia the whole of the cellular tissue was soft, and deformed, as if it had been extended, with but little power of recovering itself again, and several large irregular lacerated cavities were observed. The same appearances were remarked in Euphorbia Tirucalli, but the laceration of the tissue was much less extensive. In Hibiscus Rosa Sinensis the cells of the cortical integument (mesophlæum) were very much torn, and in Hibiscus militaris not only the cells of the bark, but especially those of the pith, were so completely broken up, that it was difficult to obtain a thin slice of those parts for examination. In no case, however, have I found any kind of tissue ruptured, except the soft cellular dodecahedral or prismatical. It would also

seem that M. Payen recognises the laceration of tissue by frost, for he ascribes the acridity of frozen potatoes to an extravasation of the acrid matter which exists in the epiphlæum of such tubers, and which, in a natural state, is locked up in the cells of which that part consists. Independently of these observations, it is not to be doubted that frost does split the tissue of plants. I saw the youngest shoots of Erica mediterranea, cinerea, and others, shivered into thousands of pieces in the Horticultural Society's Garden, on the morning of the 20th of January. The branches of Melaleucas were rent to their points at Carclew. Several cases, among others that of the common holly, were observed at Claremont, where the bark was split, and rent asunder from the wood below it; and Sir Oswald Mosley has given me the following instance, which occurred under his own observation. An oak tree, growing upon the south side of a hill, in a sheltered situation, in Knightly Park, near Burtonupon-Trent, in the county of Stafford, was rent in the severe frost of last winter in two different places, to the height of 13 ft. 3 in. There was an interval of 11 in. between the two shakes, which were each of them one quarter of an inch wide, and extended in depth to the heart of the tree. The girth of the tree is 6 ft. 10 in., and as soon as the frost went the openings closed again, and the tree is now as flourishing as ever.' To these cases many more might be added.

"The organisation of woody tissue appears to be affected, but not by laceration. If a frozen and unfrozen transverse slice of the stem of Hibiscus Rosa Sinensis be placed, side by side, upon the field of the microscope, it is obvious that the diameter of the tubes of the wood and liber is considerably less in the former than in the latter; this appears to be owing to an increase in the thickness of the sides of the tubes, which has the effect of diminishing their calibre.

"The expulsion of air from aeriferous organs, and the introduction of it into parts not intended to contain it, is a striking phænomenon.. Every one must

have remarked that when a leaf has been frozen to death, it changes colour as soon as thawed, acquiring a deeper green, and being of nearly the same depth of colour on both sides; the same appearance is produced by placing a leaf under the exhausted receiver of an air-pump, and in both cases is owing to the abstraction of air from the myriads of little air-chambers contained in the substance of this organ. If the leaf of Hibiscus Rosa Sinensis in its natural state is examined, by tearing off the parenchyma from the epidermis with violence, it will be found that the sphincter of its stomates, the cells of the epidermis, and the chambers immediately below the latter, are all distended with air; but in the frozen leaf of this plant, the air has entirely disappeared; the sphincter of the stomates is empty; the upper and under sides of the cells of the epidermis have collapsed, and touch each other, and all the cavernous parenchyma below the epidermis is transparent, as if filled with fluid. Whither the air is conveyed is not apparent; but as the stomates have evidently lost their excitability, and are in many cases open, it may be supposed, that a part of the air at least has been expelled from the leaf; and as the pith of this plant, in its natural state, contains very little air, and in the frozen state is found to be distended with air, it is also probable that a part of the gaseous matter expelled from the leaf when frozen is driven through the petiole into the pith. In the petiole of this plant are numerous annular and reticulated vessels, which under ordinary circumstances are filled with air, but after freezing are found filled with fluid; is it not possible that their functions may have been disturbed, by the violent forcing of air through them into the pith, and that when that action ceased, they were incapable of recovering from the overstrain, and filled with fluid filtering through their sides? That annular ducts are in some way affected by frost was shown by their state in a thawed branch of Euphorbia Tirucalli, when they were found in a collapsed state, empty of both air and fluid, with their sides shrivelled, and with the fibre itself, which forms the rings, also wrinkled transversely. Facts of an analogous kind were remarked by me in Erica sulphurea. The minute long-haired leaves of this species are in their natural state firm, bright green, with a rigid petiole, and upon being exposed to pressure in a compressorium, at first offer perceptible resistance to its action, and afterwards, as the pressure increases, discharge, chiefly through their petiole, a great quantity of air. But leaves of this plant, which have been frozen by exposure to the temperature of 27° are very different; they are softer, dull olive green, with a flaccid petiole, and offer but little resistance to pressure; yet, although they give way freely, the quantity of air which the compressorium expels is comparatively small, and readily driven out. Moreover, the long hairs of this plant, which in the natural state are occupied by fluid, were always found filled with air after freezing, and this without pressure having been exercised upon them.

"I am inclined to refer to this cause the well-known fact, of which many cases occurred this winter, that the sudden exposure of frozen plants to warmth will kill them; though they may not suffer if warmed gradually. In such cases, it may be supposed that the air, forced into parts not intended to contain it, is expanded violently, and thus increases the disturbance already produced by its expulsion from the proper air cavities; while, on the other hand, when the thaw is gradual, the air may retreat by degrees from its new situation without producing additional derangement of the tissue. It is also possible that leaves, from which their natural air has been expelled by the act of freezing, may, from that circumstance, have their tissue too little protected from the evaporating force of the solar rays, which we know produce a specific stimulus of a powerful kind upon those organs.

"These circumstances are, in themselves alone, sufficient to account for death being produced in plants by frost; and it is chiefly to such as these, that Professor Morren has directed his attention. It however appears to me that there are some other points of importance to which observers have not applied themselves.

66

The green colouring matter of leaves, or chlorophyll, is certainly affected

by so little as only two or three degrees of frost. In Stapelia, when thawed, it is found collected into clusters, and apparently half dissolved. In Euphorbia Tirucalli, when the plant is alive, it is extremely abundant, and consists of distinct spheroidal transparent particles, but, after a slight freezing, a considerable part of it disappears, and the remainder loses its transparency, becomes fusiform, is sometimes surrounded by coagulated gelatinous colourless matter, and many of the particles appear as if burst. In the green subcutaneous parenchyma of the leaf of Hibiscus Rosa Sinensis, the vesicles forming the sides of the air chambers are filled with distinct, angular, deep green particles, which, after freezing, become amorphous, and seem as if partially dissolved. It is possibly to the decomposition, of which these appearances are the incipient signs, that the extremely offensive odour of some frost-bitten plants, especially the Laurustinus, when thawed, is to be ascribed.

"The amylaceous matter, which is so abundant in many plants, also undergoes alteration. This has been remarked by Professor Morren, who found that when potatoes are frozen, a part of their starch disappears, leaving the deformed integuments behind it, and he suspected that the starch thus lost had furnished the sugar formed in the process of freezing this tuber. I believe it will be found a general fact, that starch is materially altered by frost, for I have always found that the amylaceous particles seem less abundant in a plant after freezing than before, and of those which remain, a part is generally becoming amorphous, clustered together, and certainly diminished in size. This is particularly striking in Hibiscus militaris. In that plant the cells of the pith abound in amylaceous granules, and are often quite filled with them; and they also occur abundantly inside the cells of the bark, of the medullary rays, and even of the tubes of the wood, and, in short, everywhere except inside the woody tubes of the liber; so that a thin slice of the stem of this plant, treated with iodine, forms a most beautiful microscopical object. But after being frozen, a great part of the starch disappears, and the particles which remain are not more than a half or quarter their former size. I have not, however, remarked among them any appearance of dissolving; neither have I been able to observe any change in the curious double-headed bodies, in form resembling dumb-bells, found in the vessels of Euphorbias, and supposed to be a state of amylaceous matter, because iodine colours them violet; they appeared to me to be in precisely the same state before and after the plant was frozen to death. M. Payen, however, denies that any starch whatever is lost in frozen potatoes (Comptes rendus, vi. 345.); but as only a small part of his important treatise on amylaceous matter has reached this country, I am unable to state in what way he explains the action of cold upon this substance.

"Finally, it appears that frost exercises a specific action upon the latex, destroying its power of motion. If, as Professor Schultz supposes, this is the vital fluid of plants, such a fact would alone account for the fatal effects of a low temperature. In all the cases I have observed frost coagulates this fluid, collecting it into amorphous masses. In Stapelia, where the laticiferous vessels are easily found, the latex itself is so transparent, that it is difficult to perceive it in a living state, even with the best glasses; but after freezing it is distinctly visible, resembling half coagulated water. In the Hibiscus above mentioned, the stem is covered with long, rigid, simple hairs, filled with a plexus of capillary laticiferous vessels of extreme tenuity, but in which the motion of the latex may be seen beautifully with the of an inch object glass of an achromatic microscope. Upon being thawed, after freezing, all this apparatus is found reduced to some misshapen separate sacs of fine grumous matter, in which no motion can be detected. That these vessels lose their vitality after freezing, may indeed be seen without the aid of a microscope; for if a stem of a Ficus elastica, or a Euphorbia, or any such plant, which discharges an abundance of milk when wounded, be first frozen, and then thawed, no milk will follow the incision.

"From these facts, I think we must draw the conclusion, that the fatal effect of frost upon plants is a more complicated action than has been supposed; of which the following are the more important phænomena :—

"1. A distension of the cellular succulent parts, often attended by laceration; and always by a destruction of their irritability.

"2. An expulsion of air from the aeriferous passages and cells.

"3. An introduction of air, either expelled from the air passages, or disengaged by the decomposition of water, into parts intended exclusively to contain fluid.

"4. A chemical decomposition of the tissue and its contents, especially of the chlorophyll.

"5. A destruction of the vitality of the latex, and a stoppage of the action of its vessels.

"6. An obstruction of the interior of the tubes of pleurenchyma, by the distension of their sides.

"These phænomena may be considered in part mechanical, in part chemical, and in part vital. The two latter are beyond our controul, and probably depend, in part, upon the quality of fluid and organic matter, which may resist the action of cold in different degrees, according to their various modifi. cations; and, in part, upon specific vitality. Salt and water freeze at various temperatures, according to the density of the mixture, from 4° to 27°; oil of turpentine at 14°; oil of bergamot at 23°; vinegar at 28°; milk at 30°; water at 32°; olive oil at 36°; oil of anise at 50°; and it is not to be doubted, that, in like manner, the fluid contents of plants, which we know are infinitely modified, will resist the action of cold in very different degrees. "The mechanical action of frost may however undoubtedly be guarded against to a great extent. It is well known, that the same plant growing in a dry climate, or in a dry soil, or in a situation thoroughly drained from water during winter, will resist much more cold, than if cultivated in a damp climate, or in wet soil, or in a place affected by water in winter. Whatever tends to render tissue moist will increase its power of conducting heat, and consequently augment the susceptibility of plants to the influence of frost; and whatever tends to diminish their humidity, will also diminish their conducting power, and with it their susceptibility; this is an invariable law, and must consequently be regarded as a fundamental principle in Horticulture, upon attention to which all success in the adaptation of plants to a climate less warm than their own will essentially depend. The destructive effects of frost upon the succulent parts of plants, or upon their tissue when in a succulent condition, may be thus accounted for, independently of the mechanical expansion of their parts; indeed, it is chiefly to that circumstance, that Dr. Neuffer ascribes the evil influence of cold in the spring; for he found, that at Tubingen nearly all trees contain 8 per cent. more of aqueous parts in March than at the end of January; and the experience of the past winter shows, that the cultivation of plants in situations too much sheltered, where they are liable to be stimulated into growth, and consequently to be filled with fluid, by the warmth and brightness of a mild protracted autumn, exposes them to the same bad consequences as growing them in damp places, or where their wood is not ripened, that is to say, exhausted of superfluous moisture, and strengthened by the deposition of solid matter, resulting from such exhaustion."

MISCELLANEOUS INTELLIGENCE.

ART. I. General Notices.

STEELE's improved Kitchen-Range.-Messrs. W. and P. Steele, the most extensive manufacturing and furnishing ironmongers in Edinburgh, have lately completed a kitchen-range which appears to us to be by far the most complete apparatus of the kind hitherto brought under public notice. Though chiefly calculated for large establishments, yet it may be so far reduced in dimensions, as to be put up for 25l.; though, for large mansions, club-houses, hotels, &c., it will cost from 50l. to 100/ There are two features in it which are new

and to us very satisfactory. 1st, A power of heating a reservoir of water at the top of the house, 100 ft. or more above the level of the boiler, from which hot water can be distributed all over the house for baths, washing, housemaid's closets, or other purposes. This has been done before, but never in such a manner as to be perfectly free from liability to accidents. 2d, A mode of cleansing the cisterns effectually, without any further trouble to servants than merely turning one or two cocks. There are roasting-ovens on the principle of Mr. Strutt's; a boiling-table, or hot hearth, like Count Rumford's; arrangements for steaming or boiling to any extent; and the whole is effected by one fire, which is open, and before which meat may be roasted in the usual manner. The drawings have been explained and detailed to us by Mr. Steele, and also to a number of London architects, and some ranges are in the course of being put up both in England and Scotland. A more detailed description will be given in the forthcoming Supplement to our Encyclopædia of Cottage Architecture; and, in the mean time, this notice will, we trust, be duly prized by such of our readers as are building, and can afford to lay out 251. or 301. for a kitchen-range.— Cond.

Ironwork coated with Gas Liquor, Tar, or Pitch, is found to be far less durable than when painted with lead and oil, in the usual manner. I do not know how to account for this chemically, but such is the fact. The oxidation is greatly accelerated in a damp situation, but it takes place even in coalscuttles kept in dry rooms. Of course the circumstance of gas liquor being unfit for preserving iron does not militate against its fitness for preserving wood.-P. S. Edinburgh, July 29. 1840.

ART. II. Domestic Notices.
ENGLAND.

ENVILLE, the Seat of the Earl of Stamford, in Worcestershire. — I last week visited Enville, being one of the few old liberally conducted establishments at the present time in existence, and sincerely hope His Lordship may live long to administer to the wants of all around him with the same generosity as heretofore. The plants, as usual, were looking remarkably well under the able superintendence of Mr. Beddard. There is a large house for orchidaceous plants, containing many rare species: there are some very fine specimens of Stanhopea, Gongòra, and dendrobiums; also a fine plant of Aérides odoratum in full flower, bearing three scapes of beautiful and delightfully scented flowers; with many others equally interesting. In the forcing department, in the management of which Mr. Beddard has for many years been so successful and celebrated, there were some very fine productions, especially pines, melons, &c.; the peaches were in finer perfection than we ever before saw any. As we enter the pleasure-grounds on the north-west side of the hall, a beautiful picture presents itself, looking over an extensive lawn and plantations. On the lawn are some of the finest specimens of ornamental trees and shrubs in England; especially some magnificent limes, one of them branching close to the ground, and measuring upwards of 110 yards in circumference; also very fine Spanish chestnuts, purple beeches, deciduous cypress, Rhús Cótinus, &c. &c. The woods and plantations, at this season of the year, present a most pleasing spectacle.-L. P. Handsworth, near Birmingham, June 23. 1840.

ART. III. The Royal Botanic Society of London, Inner Circle, Regent's Park.

THIS Society is now so far established, that, after combating many conflicting opinions, they have settled upon a highly approved design for laying out the gardens, and feel themselves in a condition to make an application to the members for the purpose of raising a sum sufficient to complete immediately the laying out of the gardens to such an extent, and in such a manner, as may gain the entire confidence of the well-wishers of the Institution.