The Action of Soot on Grubs. (p. 573.) To test the statement made in 573. of the fatal, or at least unwelcome, influence of soot on grubs, I have put two fine fellows separately in garden pots partly filled with a mixture of soot and earth, and have given them the green herbage of potato plants for food. When they have eaten what they like, they bury themselves in the mixture, regardless of the soot. — J. D., sen.

Anon.'s Device (p. 569.) for preventing the Ravages of Rooks on newlysown Corn. It would not much grieve me to see Anon. subjected to a six hours' taste of the misery to which the device he recommends must necessarily subject that truly useful bird, the rook; a bird that confides in man, that builds its nest and rears its young on the trees that shade his dwelling, that follows his plough within a few yards of the driver, and destroys the larvæ of numerous insects that would otherwise destroy his crop. Hunger may compel the rook to feed on grain; but it is too well known for me to say any thing about it, that its favourite food is insects in the larva state. But granted that the rook may be injurious to crops newly sown, is our population so thin that no children can be found for 6d. or 8d. a day each, to keep off the depredators for a few days, until the crop is up? Yes, and at less expense than Anon's infernal machines would cost him. I have repeatedly examined the crops of rooks. In six young that had been shot, the crops were nearly filled with wireworms; in the crops of others I have found the larvæ of the cockchafer, and other grubs that I am not entomologist enough to know the names of. In one or two instances, in frosty weather, I have examined the crop of one or more rooks that had been shot; it contained dung, earth, and a small portion of grain. I will just notice, that the land adjoining Mr. Wiles's rookery is yearly sown with pulse or grain, and in no instance have I known or heard that the land has, in consequence, failed of a crop. — J. D. sen.

Oct. 17. 1833. The home-made Snuff (p. 586, 587.), tested by a most experienced snufftaker, and found deficient, was sent hence on February 13.: and on May 24., when I had the pleasure to see you at Bayswater, Mr. D. showed me the snuff, the bottle which contained it being without a cork, and he informed me, that one person to whom he had submitted it compared its strength to that of the foreign snuff of the shops as 5 to 7; but that another gentleman was to give a final decision upon its merits. Now, an experienced snuff-taker knows well, that if he were to have his box of highdried Welsh open only for a day or two, its contents would become vapid, its flavour deteriorated, and its pungency materially lessened. There is, too, another circumstance that I should mention, viz., that no other substance had been added to mine, while the snuffs of the shops are never free from them. I have now some Welsh before me, brought by a friend from Lachern y Medd, a village in North Wales, where large quantities are manufactured in this I can, without difficulty, distinguish a number of white particles, gritty under the knife, which I presume to be lime, as, on sprinkling a small quantity of this snuff on the surface of some water, these particles invariably sink first; and on putting some of them, which I have picked out separately, into water, I find that they require, though they do at length dissolve, a large proportion of water to effect it. I took care that the water employed should be free from lime, and on the addition of a solution of oxalic acid, it was again precipitated. It has been always affirmed, and I believe with truth, that carbonate and muriate of ammonia, and, in moist snuffs, if not in dry, chloride of soda (common salt), are invariable ingredients. I have, to some of my own snuff, added a portion of carbonate of ammonia, and find the pungency much increased thereby, as would, from the very nature of the salt, be expected. I was not before aware that lime was ever employed; but we may easily judge of its effects from its caustic nature.-J. C. K. Levant Lodge, Oct. 23. 1833.

ART. V. Queries and Answers.

ADDITIONAL Information to that of J. D. as to the Mode of taking Impressions of the Leaves of Plants. (Vol. IX. p. 629.) — Sir, If W. Whiddon should not come forward with his method of taking the impressions of leaves, &c., the following, I hope, will meet the wishes of J. Polleck :

Directions for taking Impressions from Plants, on Cotton, Silk, Lawn, Muslin, or Linen.— The colours, which may be obtained from any chemist's, must be prepared with cold-drawn linseed oil. The balls are to be made of soft leather, and stuffed with wool. If the impressions be taken on paper, they may be coloured afterwards with any water-colour. Directions for making the Colours. Lampblack or ivory black makes black; king's yellow or orpiment makes yellow; Prussian blue and king's yellow, added together, make green; rose pink or drop lake makes pink; smalt or Prussian blue makes blue; vermilion or carmine makes red. A thimbleful of roche alum, added to one ounce of any of the above colours, will make them stand washing and wearing.

I am entirely of opinion, with J. D., that " no practical advantage seems derivable from this knowledge (the knowledge itself is very well); for dried specimens of leaves, and such other flat objects as one can take profiles of by means of it, are far more useful, and as easily prepared." I had all the necessary implements for the process, and took many impressions, but I gave it over as waste of time, compared with that employed in preparing specimens themselves. If the botanical knowledge of plants be the end in view, the, I may almost say, indelible, impression of the name and habit of the species, left on the mind by the necessary attention and labour attendant on drying them, and afterwards anointing them with a mixture of the muriate of mercury and camphorated spirits of wine, for their final preservation from insects, is of quadruple the importance, in promoting the knowledge or remembrance of them, that taking the mere profiles of their leaves is. Indeed, if a person has in his possession the Encyclopædia of Plants and Hortus Britannicus, and understands botanical terms (which, if he does not, they will explain to him), he may almost determine the name of any species contained in these volumes. -I am, Sir, yours, &c. ·George Thomson. High Elms, Oct. 26. 1833.

By what harmless Means can Martins and Swallows be induced to cease building and breeding in the Places in which they have been long allowed to build and breed? The affection for locality is so strong in the swallow and martin, that they can scarcely be driven away from an old establishment. Chicherley Hall, Bucks, having for several years been neglected, a free opportunity has been given to the birds to affix to it some hundreds of nests in a season, under the cornice of the mansion. Last year, I tried to scare them away by nets, feathers, gas tar, destroying their nests, &c., and all to no purpose. [The martin has been known to renew its nest four times in one season, in one place.] As I do not wish to kill the little creatures, I solicit some correspondent to inform me of a means by which I can drive them away. William Whiddon. Chicherley Hall, Bucks, Feb. 28. 1833.

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To this query, which we have published in the Magazine of Natural History (vol. vi. p. 456.), a correspondent (Mr. Fennell) has replied, and recommended Mr. Whiddon " to obviate the possibility of the swallows' and martins' being at the trouble of erecting their nests, by spreading a thick coating of soap upon the sides of such places as the birds have been in the habit of appropriating to their own use. Whenever the birds attempt to stick their muddy materials up, its moisture will moisten the soap, and the sliminess of this will prevent the adherence of the muddy mate

rial, and cause it to fall down upon the earth. I believe this to be an old plan, and an effectual one."

The Elms in Camberwell Grove, &c. (p. 630.) —I cannot answer the query in this case, having never seen the elms in Paris; but their producing abundance of seed is no criterion of distinction. A green-house plant will sometimes flower better in a poor man's window than in a firstrate green-house under a first-rate gardener. The question is too vague to be answered. I believe there are as many varieties of oaks and elms in England as there are of apples and pears. Agronome. Oct. 29. 1833. The Lag in Timber. (p.629.)—An experienced forester can as readily discern when a tree is affected with the lag, as an experienced shepherd can discern when his sheep is affected with the rot; and the knife for the sheep and the axe for the tree are the best remedies for each. The immediate cause of the disease (the lag) may, however, be generally traced back to a wet summer and an early winter; such as those of the year 1816 and the year 1822. The alburnum in these seasons never got thoroughly ripened, because the leaves had not a chance of finishing their labours of pumping off the extra-moisture; and as the tree, in such a case, becomes top-heavy, and is easily blown about by the winds, the weakest circle fails first. Agronome. Oct. 29. 1833.

Treatment of a Plantation of young Oaks. Your correspondent, "A Reader " (p. 630.) should by no means cut down his young oaks, but should prune them well and properly for ten or twelve years to come; that is, with a long chisel and mallet, to strike off all rival leaders, and all such boughs as intrude upon the adjoining trees. Should any of the trees have a head like a besom, weed out three fourths of it, preserving a leader. Should the trees be only 4 ft. apart, they may stand thus till every one is fit for sawing down into two 9-ft. rails. Then the forester should keep on felling the worst every year, till the trees stand about 20 ft. asunder, when he must leave the estate to his son. Agronome. Oct. 1833. Treatment of a Plantation of young Oaks. (p. 630.)- Assuming the soil to be favourable to the quick growth of oak, from that tree having been selected, I would cut down, as soon as they will peel, in the spring, as many of the trees as will leave a crop for timber, standing at least 60 ft. apart, and cut them very carefully 3 or 4 in. above the ground, so as not to injure or wound the stool. If the trees are left thicker than I have mentioned, they will materially injure the growth from the stools. I should not recommend an increase of the stools by layering; because, although new stools will be thereby more quickly established, they will, of necessity, be much too near together. A great deal of produce is sacrificed annually in coppices, as in most other crops, by filling them up too closely, and thereby excluding the sun and air, so essential to their fertility. I am strongly inclined to think that, where oak coppice thrives well, the stool, in a given number of years, will pay better than the timber; the bark of the young growths being very superior in quality; but an owner of woodland in Herefordshire would be a better authority for "A Reader's" guide than I am. - Charles Lawrence. Cirencester, Oct. 4. 1833. Treatment of a Plantation of young Oaks. (p. 630.) — “ A Reader" would more readily have obtained an answer to his query, had he entered a little more into details, and stated the exposure, and the quality of the soil, of his plantation ground, and also the distance at which the trees at present stand from each other, &c. If the oaks have been planted at what is generally admitted to be the proper distance, viz. 8 ft. apart every way, then the most profitable method of managing the plantation is turning it into copsewood; as, if allowed to remain long at this distance, even "A Reader" will, I think, on reflection, confess that it is quite impossible for them to become useful timber. Supposing this to be the case, I would advise, without further delay, that the plantation should be thinned out;

leaving the trees 18 ft. or 24 ft. apart; varying this distance, less or more, in favour of a better tree. The bark obtained at this cutting will more than meet the expense of labour, and the wood will make superior charcoal. From fifteen to twenty years hence, when the coppice is ready for a second cutting, "A Reader" will be able to judge what number of trees should be left as permanent standards of those reserved at the first cutting. Most of these trees will by that time have arrived at a bearing state; and "A Reader" will do well to select as many as possible, for the permanent standards, of Quércus Ròbur, in preference to Q. sessiliffòra; the latter yielding the least valuable timber. Such of the trees reserved at the first cutting, as now require to be removed, will turn to good account in bark, and the wood at this age will be fit for various useful purposes. Having said thus much, I trust it is hardly necessary to remind " A Reader" of the impropriety of thinning out to the permanent distance at once; for, if the plantation be as thick of trees as it ought to be, to lay it open at once might be too great a transition, and consequently hurtful to the remaining standards; which is a sufficient evil of itself, independently of the depreciation of bark and timber which such a course would effect. With regard to laying down branches of oaks, for filling up blanks in the plantation, that may be done any time between November and April. It is, however, more a curious, than useful, piece of cultivation; and I would recommend employing stout young oak plants, at once, to fill up blanks; say 3 ft. to 3 ft. high. Such plants can be had for from 35s. to 40s. per 1000. In cutting coppice wood, perhaps the following hints might be worth " A Reader's" consideration: — Oak should not be cut until the leaves are nearly full-blown; otherwise the bark cannot be separated from the wood to any advantage. In Scotland, the cutting of coppices seldom commences before the first week of June: before the stools throw out the young suckers, four or six weeks more elapse; and before these shoots are ripened the winter sets in. The consequence is, that all, or the greater part, of these shoots are partially destroyed; and this circumstance causes a numerous increase of laterals in the following summer; by which the stool is materially weakened, and the cutting of the coppice wood retarded two or three years at least. To obviate this defect of our climate, I once tried the following experiment, which, although not upon a scale sufficiently extensive to warrant my recommending it in preference to any other mode, yet, I must say, produced a result which was so much to my satisfaction, that I do certainly consider it worthy of a trial upon a larger scale: On the 1st of November, 1825, after having pitched on six young oak trees, 5 or 6 inches in diameter, I cut off the communication between the root and top by the bark: this I accomplished by cutting out a piece of bark, about an inch broad, all round the tree, 2 or 3 inches above the surface of the ground. My motive for this was, to let the stool have the full advantage of the returning spring growth. On the 4th of June following, when I came to cut these trees down, I found them in full leaf, or nearly so, with suckers below the part where the bark was cut out; several of which were 3 in. and 4 in. in diameter, and two of them nearly 6 in. in length. A little attention was necessary in cutting down the heads from the stools, which I performed with a small pruning saw, in the month of July. I thinned the suckers on the stools, so as to leave only five on each. These ripened well, and made from 5 ft. to 7 ft. of wood in the course of the season: however, in the ensuing winter they were mostly eaten down to within 6 in. of the stools by hares. I cannot understand what tempts gentlemen to harbour these confounded vermin about them. Cutting with the saw may be considered a more expensive operation than with the axe; but if, as I believe, it has a tendency to advance the growth of the coppice by two or three years, perhaps it is VOL. IX. No. 47.

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the cheapest in the end. One advantage of using the saw is, that the roots of the stool are not shaken by it, as they are by the stroke of the axe; and taking out a piece of the bark, or ringing as it is termed, in the early part of the winter, is also advantageous, in as far as, before the top is cut off, the bark is firmly united to the wood of the stool; by means of which there is no shrinking, as is the case when the bark and wood are cut at the same time and the sap is rising. Consequently there is no opening between the wood and bark for the lodgement of rain-water, or moisture of any kind, to cause the stool to decay. I am, Sir, yours, &c.— James Munro. Brechin Nursery, Oct. 1833.

The Box Tree. As the wood of this tree is now greatly in demand for the wood cutters (see Penny Magazine, supplement for Oct.), how far would it be worth while to make plantations of it in those parts of England where it is understood to have been formerly abundant? How many years would the tree require before its trunk became fit for use? Would it be advisable to try the Balearic box? —E. H. Green. October, 1833.

Pumping. · What disease among larch trees is meant by this term, used in p. 553.? W. T. Bree. Allesley Rectory, Oct. 19. 1833.

The Female of the Lombardy or Turin Poplar (Populus dilatàta L.).— Has it yet been established in this country? In 1830 it was in Vol. VI. p. 419.) stated that M. C. A. Fischer, of the Göttingen botanic garden, had succeeded in finding one female tree amongst many thousand male ones around Göttingen, and that he had sent cuttings of it to the Botanic Garden at Bury St. Edmunds, which had failed to grow. — C. M. W. London, Sept. 10. 1833.

On cultivating Xanthochỳmus tinctòrius Rox., in relation to the Question on cultivating the Mangosteen, asked in p. 378.-J. B., in asking, in p. 378., for information on the method of so cultivating the mangosteen in Europe as to cause it to produce fruit, refers to your mention, in p. 150., of the mangosteen's being in cultivation in M. Boursault's collection. You have joined J. B. in requesting some facts on our mode of training this plant, which I readily communicate; but it unfortunately happens that the plant you have mentioned as the true mangosteen (Garcínia Mangostana L.) is not that species, but the Xanthochymus tinctòrius Rox., figured in Roxburgh's work, The Plants of the Coast of Coromandel, t. 196. With regard to this latter plant, M. David, of whom you have spoken in p. 147., has communicated to me the following facts: His tree is growing in a round box, 18 in. in diameter, plunged in a bark bed in the stove. The soil which agrees with it is pure heath mould, or rather heath mould, mixed with common garden soil, or turfy loam. The plant is 5 or 6 feet in height, and is devoid of branches for 2 or 3 feet up; the branches then commence, and form a rounded head, of no very great circumference. It is not upon a trellis. The stem at the bottom is not so thick as my wrist. The plant bears fruits as large as fine green gage plums (belles Reines Claudes), either single, or more frequently united in twos, threes, or fours, and with flavescent flowers. It has borne fruit for several years, and receives no particular treatment. It is necessary that it be kept in a hot and moist atmosphere, in a good hot-house; but, above all, the roots of the plant should be constantly kept very warm. If the heat of the tan be weakened, or if the plant be kept any time out of the tan, it is immediately perceivable by the foliage. The fruit, M. David states, is delicious, and always cool, although gathered in a very warm atmosphere, and eaten immediately. M. David has raised several plants from the seed of his tree, which appear to be as vigorous as their parent. He has now two about 18 in. in height, both of which are thriving very well.-L. L. L. Paris, July 6. 1833.