dropped gradually and evenly, unlike what they did with ether, in which case the petioles literally fell down to a degree beyond that with amylene and chloroform. The following difference was, however observable:-In the two latter the falling of the leaf-stalks was always accompanied by folding of the pinnæ, while with ether that was not the case, showing that with it the effect was more local. When amylene was employed, the recovery from anaesthesia was very speedy compared with what it was when chloroform or ether was used. Moreover, the pinnæ, when touched with amylene, folded from apex to base with an increasing rapidity, till they sometimes became confused. This was very unlike the regular, and, if we may so call it, deliberate folding that took place with chloroform. With amylene, however, the pinne were always closely appressed, while with chloroform they were rarely so. With ether the effect did not show for some seconds, the number of which constantly varied. 2. On the Primary Use of Ammonia in Vegetable Nutrition. By Major JOHN H. HALL. The importance assigned to nitrogen in agricultural chemistry in the present day is a fact well known to all. It has come to be taken as the ultimate measure of the value of organic manures, and an analysis is not considered complete without specifying the quantitative amount of nitrogen which a manure contains. Observation of the avidity or capacity for ammonia which plants universally manifest has no doubt originally led to the conclusion that it contains something which must be highly beneficial in the economy of vegetable life. As ammonia is composed of hydrogen and nitrogen, the selection of the latter ingredient as the measure of value to the disregard of its other constituent, expresses a positive view or theory as to nitrogen being the all important element in ammonia which renders it so essential in the growth of plants. But I have never met with any satisfactory explanation of the grounds on which this estimate of the value and importance of nitrogen rests as an element of vegetable nutrition. I think that the true measure of the requirements by plants of any given substance should be found in the amount in which the substance enters into their composition. Now, an examination of the chemical constituents of vegetable substances shows that nitrogen enters very partially into them. Thus some of the most abundant of vegetable substances are entirely destitute of nitrogen. Cellulose, the structural basis of the roots, stems, leaves of plants, contains no nitrogen. Starch, gum, sugar, wax, oils, resins, some of the most abundant of vegetable products, are also destitute of it. Gluten is almost the only form or combination in which nitrogen occurs in plants, and it exists in them in small and variable quantities—in the seeds and fruits of some, and in the leaves of others; and it occurs for the most part in these plants and their products which constitute the food of man and animals, while the chemical constituents of plants fail to give evidence of their having any very great capacity for nitrogen. On the other hand, chemical experiments show the presence of hydrogen in every kind and form of vegetable matter. Its universality is on a par with that of carbon, and it is a remarkable circumstance, that it preserves a close relation with that substance, and generally follows it in the variations of its proportions in vegetable substances. These considerations led me to the conclusion, that the primary use of ammonia in the vegetable economy must be to supply hydrogen, to form in conjunction with carbon the hydro-carbonaceous material which forms the basis of all vegetable structures and productions, and that this alone can explain the reason why plants manifest such a universal avidity or capacity for ammonia. Not that I would question for a moment the concurrent use of ammonia in furnishing nitrogen to whatever extent the special requirements of particular plants may render necessary; but, looking to the very limited and partial extent in which it is found in vegetable productions, I apprehend it can never account for the universal capacity of plants for ammonia; and it seems to me, to say the least, a transposition and misuse of terms-the substitution of the minor and partial effect for the major and universal one-to regard ammonia only with reference to the constituent which has the least place in the vegetable economy, and to overlook that one which, equally with carbon, constitutes the universal pabulum of the vegetable creation. Major Hall then exhibited two plants of spinage, one of which had been watered simply with the common water of Edinburgh, and the other with a solution of carbonate of ammonia, and pointed out the great size which the latter plant had attained when compared with the former. The effects he endeavoured to trace mainly to the hydrogen in its combination with carbon. Several members expressed doubts as to the correctness of Major Hall's conclusions, and pointed out the presence of nitrogen in the protoplasm or formative matter of plants as having been overlooked by him. It was stated to be the general belief of vegetable physiologists that no active cellformation could go on without the presence of nitrogen, and that ammonia, whether in the atmosphere or in manures, was valuable in supplying this. Dr Balfour exhibited a stem of Astrapca Wallichiana, yielding a large quantity of mucilage. When the stem is cut and put into alcohol the exudation of this mucilage becomes very evident. Dr Balfour also noticed that some stems of the Banana in the Botanic Garden, when allowed to dry after being cut down, showed a large quantity of white crystals on their surface. These had been analysed by Dr Simpson in the University laboratory, and had been found to consist of chloride of potassium. Dr Maclagan, Berwick, sent roots of an elder tree, taken from a waterpipe, accompanied with the following note :-"The enclosed production was brought to me by the Superintendent of Works here. When moist it was much more bulky, but the radicles very brittle. It occupied and completely obstructed the main six-inch water-pipe, leading from the reservoir into the town of Berwick. The pipe is eight feet deep, and covered over with clay-puddle, through all which, and through some fissure at a joint, the small rootlet had penetrated. I asked what were the nearest plants, and found that two elders were suspected of being the culprits, and that they had been accordingly eradicated." Thursday, 12th January 1860.-Professor ALLMAN, President, The following Communications were read : 1. Sketches of Caithness and its Botany, with a List of the Phanerogamous Plants and Ferns. By ROBERT BROWN. This paper was the narrative of a botanical tour made in the autumn of 1859 in the County of Caithness, the Flora of which is by no means well known. The author, after giving an outline of the physical geography of the county and sketches of its scenery, proceeded to describe its vegetation. The only indigenous trees of Caithness were stated to be Populus tremula, Betula alba, Corylus Avellana, and Pyrus aucuparia, and it was remarked that the specimens of these were comparatively stunted. The county however appears at one time to have been covered with forests, numerous trees being annually dug up in the bogs. Trees, when planted, require to be protected from the sea breezes. The common crops of the fields (fenced into octagons, hexagons, heptagons, squares, and triangles, by what the geometry of the farmer accounts straight lines of upright flags) are excellent clover, grass, turnips (introduced within the last forty years), barley, bere or big (Hordeum hexastichon). Potatoes were only introduced about one hundred years ago; and though now extensively cultivated, were at first, for a number of years, limited to gentlemen's gardens. Before the introduction of potatoes, most of the ground now appropriated to them was devoted to the cultivation of cabbages, which constituted the principal vegetable food of the poorer classes. The common culinary vegetables grow well; but fruit trees, unless protected by a high wall with southern exposure, produce but indifferent fruit. Most of the crops are considerably later in coming to perfection than in the southern counties. For some time after Mr Brown arrived (July 31st), the hedges were pink with the wild roses, the haymakers were busy at their work for about three weeks, and the crops were not begun to be generally cut until the 1st of September. On Dunnett Links, the bent (Ammophila arundinacea) is instrumental in preventing the sand from blowing inward as formerly, spreading desolation for a great distance around. Many of the wild plants are applied to economic purposes-for instance, the pith of the common rush as wicks for the oil-lamps of the peasantry; heather for mats, ropes, &c. The number of the wild plants enumerated by Mr Brown was 419, exclusive of those introduced, &c., and about 29 well-marked varieties; but probably the number might be considerably increased. Mr Robert Dick of Thurso had been examining the Flora for many years, and to him, along with Mr C. W. Peach of Wick, the well known naturalist, the author had to tender his best thanks for the valuable assistance they had given him in drawing up this paper. The following species are not noticed in Mr Watson's most valuable Cybele Britannica" (vols. 1-4), as occurring in his "North Highland" province (Ross and Cromarty, Sutherland and Caithness). Those regarding which further researches would be desirable are marked with a point of interrogation:-Ranunculus bulbosus, Papaver Rhoas, Plantago Coronopus (ballast), Cardamine impatiens (?), Viola odorata, Drosera intermedia, Tilia parvifolia, Hypericum humifusum, Prunus avium, Pyrus Malus (Westfield), Berberis vulgaris(hedges), Ribes alpinum, Saxifraga tridactylites, Egopodium Podagraria, Valeriana dioica, Hieracium prenantboides, Hieracium boreale, Antennaria dioica, Petasites vulgaris, Polemonium cæruleum? (outcast), Convolvulus sepium, Veronica polita, Myosotis palustris, Anagallis arvensis, Salsola Kali (ballast), Rumex sanguineus, Potamogeton plantagineus (?), Luzula Forsteri (?), Carex teretiuscula, Alopecurus fulvus, Alopecurus agrestis, Avena pubescens, Arrhenatherum avenaceum, Glyceria distans, Bromus sterilis, Hordeum murinum, Lastrea Fonisecii, Equisetum umbrosum (common). The following may be also noticed as being species extending far north in Scotland, and not perhaps hitherto recorded in Caithness:-Ranunculus hederaceus, Arabis hirsuta, Barbarea vulgaris, Sisymbrium Sophia, Silene inflata, Lychnis vespertina, Hypericum quadrangulum, Erodium cicutarium, Geranium dissectum, Spartium scoparium, Prunus Padus, Geum urbanum, Alchemilla alpina, Pyrus Aria, Saxifraga stellaris, Sanicula europæa, Charophyllum temulum, Myrrhis odorata, Sambucus Ebulus, Sherardia arvensis, Tragopogon pratensis (Reay Links), Hieracium vulgatum, Hieracium umbellatum, Carduus heterophyllus, Aster Tripolium (Mr Peach, Wick), Pyrethrum Parthenium, Scrophularia nodosa (?), Au chusa sempervirens, Pinguicula lusitanica, Lysimachia nemorum, Habenaria bifolia (Peach), Juncus balticus, Carex distans, C. limosa, C. pilulifera, Sesleria cærulea, Koeleria cristata, Festuca bromoides, Cystopteris fragilis, Asplenium Ruta-muraria, Isoetes lacustris. Besides these there were noticed several other plants, which, though they have no effect in a phyto-geographical point of view, are yet interesting; such as-Draba incana, Vicia Cracca, Rosa canina (b. sarmentacea, Woods), Parnassia palustris (very common), Hieracium vulgatum (e. maculatum, Gm.), Cichorium_Intybus (outcast), Antennaria dioica (b. norvegicum, Jacq.), Tussilago Farfara, Arctostaphylos alpina (Ben Shurraii), Menyanthes trifoliata, Nepeta Glechoma, Ajuga pyramidalis, Myosotis cæspitosa, Primula Scotica (very common), Euphorbia Helioscopia, Listera cordata, Potamogeton crispus, Sparganium simplex, Carex acuta, Hierochloe borealis, Asplenium Filix-foemina, b. rhæticum (Roth.), c. molle (Hoffm.), Osmunda regalis, Lycopodium annotinum. Many of those last have not been published as having been noticed in the county. So little has the botany been attended to by publishing naturalists, although the geology and zoology of the district have furnished valuable additions to the British Fossil and recent Fauna. The author had not attended particularly to the cryptogamic botany of the county, although this department would reward research. Such lichens as Bæomyces roseus, Parmelia saxatilis, Parmelia physodes, Borrera tenella, Ramalina scopulorum, Lecanora subfusca and tartarea, Lecidea æruginosa, &c., are common. 2. Notice of a Physiological Peculiarity in a specimen of Tropaeolum majus. By CHRISTOPHER DRESSER, Esq. Communicated by ALEXANDER DICKSON, Esq. The author recorded a phenomenon which he had observed in a plant of Tropaeolum majus growing in a damp part of one of his greenhouses. A pendant shoot of this plant had by accident become so much bruised and constricted, at a point about twelve inches from its extremity, as to prevent the transmission of sap from the root to the extremity of the branch, the terminal portions being connected with the rest of the plant merely by a fragment of withered bark and dried wood. This terminal portion, instead of presenting the very slight hairiness found in the ordinary state of the plant, had become extremely villous, the leaves being densely covered with white-looking hairs, so as to be quite velvety. The hairs were more densely congregated on the leaves than on the axis, and more so on the distal younger portions than on those nearer the seat of structure, this latter circumstance, probably resulting from the hairs not being separated by the expansion of growth. The hairs on the petioles measured about th orth of an inch, being rather longer than those on the laminæ. The hairs were equally distributed over both surfaces of the leaf, and appeared to be a little longer on the veins. The author alludes to the power possessed by hairs of absorbing dew, &c., and concludes that this portion of the plant had for weeks been nourished by the agency of these hairs; also that these organs were developed specially for the accomplishment of this end, since, in the ordinary condition of this plant, the hairs are extremely small and not numerous. The author draws the inference that hairs are of little value as furnishing specific characters, since certain plants at least can and do protrude hairs under certain conditions. 3. Notes on Californian Trees. Part II. By ANDREW MURRAY, Esq. (This Paper appears in the present No. of the Journal). 338 SCIENTIFIC INTELLIGENCE. BOTANY. : Flora of Ceylon.-From the identity of position and climate, and the apparent similarity of soil between Ceylon and the southern extremity of the Indian peninsula, a corresponding agreement might be expected between their vegetable productions and accordingly in its aspects and subdivisions Ceylon participates in those distinctive features which the monsoons have imparted respectively to the opposite shores of Hindustan. The western coast being exposed to the milder influence of the south-west wind, shows luxuriant vegetation, the result of its humid and temperate climate; whilst the eastern, like Coromandel, has a comparatively dry and arid aspect, produced by the hot winds which blow for half the year. The littoral vegetation of the seaborde exhibits little variation from that common throughout the Eastern Archipelago; but it wants the Phonix paludosa, a dwarf datepalm, which literally covers the islands of the Sunderbunds at the delta of the Ganges. A dense growth of mangroves (Rhizophora Candelaria, Kandelia Rheedei, Bruguiere gymnorhiza) occupies the shore, beneath whose over-arching roots the ripple of the sea washes unseen over the muddy beach. Retiring from the strand, there are groups of Sonneratia, Avicennia, Heritiera, and Pandanus; the latter with a stem like a dwarf palm, round which the serrated leaves ascend in spiral convolutions till they terminate in a pendulous crown, from which drop the amber clusters of beautiful but uneatable fruit, with a close resemblance in shape and colour to that of the pine-apple, from which, and from the peculiar arrangement of the leaves, the plant has acquired its name of the Screw-pine. A little further inland, the sandy plains are covered by a thorny jungle, the plants of which are the same as those of the Carnatic, the climate being alike; and wherever man has encroached on the solitude, groves of coco-nut palms mark the vicinity of his habitations. Remote from the sea, the level country of the north has a flora almost identical with that of Coromandel; but the arid nature of the Ceylon soil, and its drier atmosphere, is attested by the greater proportion of euphorbias and fleshy shrubs, as well as by the wiry and stunted nature of the trees, their smaller leaves, and thorny stems and branches. Conspicuous amongst them are acacias of many kinds, Cathartocarpus Fistula, the wood apple (Feronia elephantum), and the mustard tree of Scripture (Salvadora persica), which extends from Ceylon to the Holy Land. The margosa (Azadirachta indica), the satin wood, the Ceylon oak, and the tamarind and ebony, are examples of the larger trees; and in the extreme north and west, the Palmyra palm takes the place of the coco-nut, and not only lines the shore, but fills the landscape on every side with its shady and prolific groves. Proceeding southward on the western coast, the acacias disappear, and the greater profusion of vegetation, the taller growth of the timber, and the darker tinge of the foliage, all attest the influence of the increased moisture both from the rivers and the rains. The brilliant Ixoras, Erythrinas, Buteas, Jonesias, |