Rats, mice, ants, and cock-roaches are destructive to silk worms in all stages of their existence, and must be guarded against.

Whenever these indications are observed, prepa- | about ten days from the time the cocoons were ration should be made for their accommodation finished, the moths will come out, and couple, with the wisps of straw, or other means. But few when they should be placed on sheets of paper, will ascend at first, but in the course of the first the room darkened, and left to themselves. They and second day they will nearly all have mounted. will separate of themselves, and the females will They must be looked to occasionally, and those that deposite their eggs on the papers. As soon as the not readily mount should be put upon the straw papers are covered with eggs, they should be rolled by hand. The room should be darkened, and kept up, and placed in some metal or earthen vessel, so from the commencement of the spinning, as they and kept in a cellar or ice-house till wanted next always mount and spin more readily in the dark year. Be careful not to close them air-tight, or the than in the glare of light. If the weather be dry, eggs will be killed, as they require the aid of air the ventilators should also be opened, and as much just as much as animals do. air given them as possible, without producing a current of wind. If the weather be damp, it should be dried, and kept so till the cocoons are finished. During the whole process of feeding and spin- Silk worm eggs are not injured by any degree ning, the cocoonery should be kept quiet; but this of cold; but they should not be exposed to great is particularly necessary while the worms are spin-changes of temperature suddenly; for this reason, ning. I once tried an experiment of the effect of they should be put in a cellar or an ice-house, and a sudden shock upon them while spinning. When they had been two days at work, I let a large weight fall upon the floor; it made a loud noise, and jarred the house considerably. On reeling the cocoons, I found the fibre was broken invariably, when they were about half wound off. Various other experiments satisfied me that they require quietude to enable them to finish the cocoon with an uninterrupted fibre.

The worms generally require about four days to finish the cocoon; but they should generally be left undisturbed six to eight days from the time of the last of their mounting, when the cocoons should be gathered and reeled immediately, or cured for future reeling.

kept constantly there till wanted for hatching. If kept in an ice-house from the time they are first laid, they may be kept from hatching till the latter part of the next summer, and thus successive crops may be reared. I am not prepared to say, however, that successive crops will be found profitable. I still believe that one crop, at the proper season, will be found ultimately the most profitable. I also think it very probable that keeping the eggs from hatching much beyond the natural period, will be very likely to injure the constitution of the insects. If this plan be resorted to, therefore, I would recommend that eggs for next year's use be always produced from the first crop. This plan will obviate all difficulty on that score, as the Curing the Cocoons. Various expedients are re-worms of the first crop will never be subjected to sorted to for smothering the chrysalis in the cocoon. In Europe, they bake them in ovens constructed for the purpose--the heat being regulated so as to prevent scorching the silk. The heat of the sun in this country is generally sufficient to kill them, and it is recommended as the simplest process by various writers. They spread the cocoons out for several days to the sun, until they become dry, when they may be put away in a dry room for future use. Great care is necessary, however; for, if they are not killed, the moths will make their way out of the cocoons, and thus spoil them; and if the cocoons be stored before the chrysales are sufficiently dry, the moisture will spoil the cocoons. A little experience will enable any one to judge when they are properly cured. When they are thoroughly dry or cured, the chrysales can be rubbed into powder with the thumb and fingers. Believing this plan to be the best, it is deemed unnecessary to describe the others.

If time allow of its being done, the cocoons should be reeled without curing, as they reel much more easily than when dried.

the protracting treatment. Besides, you will then always be sure of a supply of eggs for next year, whatever accident may befal the succeeding crops.

Diseases of Silk Worms.-The French and Italians describe many diseases to which silk worms are subject, and attribute them to various causes. Cleanliness and pure dry air, however, are the only preventives, as well as remedies, and it is, therefore, deemed unnecessary to go into details. Those who keep their cocooneries properly ventilated, and free from damp, and their hurdles clean, will have no diseased worms; or, if disease does occur under such circumstances, there is no remedy for it, the cause being attributable, probably, to some mismanagement of the eggs, or the worms from which the eggs were obtained having been unhealthy. When disease is caused by foul air, arising from filthy hurdles, or other effluvium, the cause of the foul air must be immediately removed, by cleaning the hurdles, and removing the filth, and sprinkling the floor with a solution of either the chlorides of lime or soda. The diseased worms should also be immediately removed.

Providing Eggs.-Before curing the cocoons, enough should be selected to produce eggs for the next season. They should be the best; for, we It is a good plan to have a couple of days' supmust infer that the worm that makes the best co-ply of leaves always gathered beforehand; so coon was in the best state of health, and will be that, in case of rain, feeding with wet leaves may most likely to have the most healthy progeny. be avoided. The importance of avoiding wet Two hundred and thirty cocoons will make an leaves will be learned from experience by all who ounce of eggs, or 40,000; but in selecting them, neglect the precept. it is best to take two hundred and fifty for each ounce of eggs required for next season, that due allowance may be made for losses from various circumstaces, such as death of moths, &c. These cocoons should be spread out on a table, and in

I must conclude this long chapter with the remark, that notwithstanding the long time necessarially occupied in the description, the practical operator will find the whole art of raising silk worms exceedingly simple, and easy of perfor

mance, and entirely within the capacity of the attributable to the immediate locality. These most ordinary persons. Little children readily hints may prove useful to many of my readers in comprehend, and can perform the whole, after the choice of their summer residences, which once practising it; and they would never require ought to be a few miles from any locality to geneadult supervision, but for their liability to negli-rate malaria. gence. All capacities are capable of performing, but few of directing the work. The art of silkmaking, though simple and easily acquired in all its parts, requires the strictest attention, that every act, though extremely simple in itself, be done at the proper time, and in the proper manner.

MALARIA—ITS EFFECTS IN PRODUCING COUN- the mouth of the Tiber, it was observed that one

or two of the ships which lay closest to the shore, began to be affected by the pernicious vapor from the land, whilst some lying further out at sea, Mr. Editor-Believing that the following re-at but a very small distance from the former, had marks on the laws which govern the production and propagation of malaria, may in a measure be useful and interesting to many of your readers, from the fact of the prevalence and fatality of what is termed country fever amongst our inhabitants, and especially the agricultural portion, I have been induced to submit them to you for your journal, if you think them worthy of a place in its pages. I have condensed the subject very much, from the circumstance of the limit of a journal like this, and have only detailed some very striking facts which cannot fail to be interesting.

large buildings, one part being perfectly healthy, and the other not so. It is said, that in the extensive hospital of St. Spirito, in Rome, the wards to the south and south-east are sickly, and the others quite healthy. We might mention many similar examples, which although highly interesting, we are compelled to omit, as we must proceed to examine some of the most evident causes of the increased unhealthiness of the low country of this state.

Hippocrates, to prove its beneficial effects. Napo- | this can be accounted for on the same principle, leon, whose mind was ever observant and active, one row of houses being more exposed than the tested it in one of his campaigns in Italy, and suc- other. This has even been noticed as regards ceeded in preserving the health of his soldiers. A very strong case in point is cited on good authority. An individual, engaged in cutting wood in Africa, found that his work could not be carried on during the summer months, in consequence of the fever prevailing among the laborers. By way of expedient, he constructed a large number of earthern furnaces in the immediate vicinity, where the laborers were at work, and kept them constantly supplied with fuel, which burned all day; the result was, that before he made this arrange- The change in the cultivation of rice from inland ment, he had from 40 to 50 men sick a day, when to river-swamps, I have no doubt, is a very fruitin a short period they were reduced from 12 to 1. ful cause. The deleterious effect of this change The night is dangerous too, on account of its was to leave an immense extent of rice-fields being the time when we seek relief and rest from abounding with stubble, from which, is said by the fatigues of the day in sleep; the consequent the inhabitants of India, the poison is chiefly prorelaxation produced by this state of the human duced; and not being cultivated, there is always system, renders man more liable to disease when a sufficient quantity of water to do all the mischief. asleep, then awake. During the prevalence of Extensive rice fields have been allowed to lay the fatal scourge, the cholera, which has devas-waste, by falling into the hands of individuals tated so large a portion of the inhabitants of the earth, it was noticed by every one that the majority of cases were attacked at night.

who had not the means of cultivating them. It is through this agency that we account for the sickness which now prevails in situations where the inhabitants spent their summers formerly, when every place was under high cultivation.

The

Malaria is also intercepted by trees with thick foliage, attributed to mere mechanical obstruction, the vapor settling in the foliage. The late Dr. Faust, of Columbia, in a treatise on malaria, has given a chymical explanation of this fact. He remarks, that "it is probable that the carburetted hydrogen accompanying the water, is obsorbed by the trees, and being decomposed, contributes to their growth in the same manner as carbonic acid." I am inclined to think that the utility of trees in preventing the propagation of malaria, is to be attributed much, if not more, to the mechanical obstruction which they afford, as the chymical change which takes place during the process of vegetation; for high fences or walls have afforded the same protection. In Rome, during the sickly season, the most prudent inhabitants, conscious of this fact, retire into their houses at sunset, close the windows and doors, and will not allow them to be opened until the sun has been up long enough to dissipate the fog. In this way they have kept from contracting fever, when their near neighbors, not making use of the same salutary precaution, have sickened and died. Dr. James Johnson, who has bestowed much attentionon During the summer of 1834, when the space this subject, in his work on Tropical Climates, re- in front of the Citadel, in this city, was in a state marks: "During my residence near the marshes of preparation by ploughing the land, in order to of Languedoc, I lived near a very fine building level it for a parade ground, yellow fever, of a formerly the convent Franquevaux, erected on the very malignant nature, attacked the soldiers, very border of the marshes. The monks in the which I have no doubt was caused, if not aggrahouse were perfectly healthy, though few of the in-vated, by the exposure of the land; there were habitants of the environs escaped disease in summer or autumn. Tradition nevertheless relates, that they were accustomed in hot weather, to sleep on a terrace contiguous to the convent, a sure method of exposing themselves to disorders; but they were sheltered by a tent of double or triple convass, and this simple precaution, necessary against the mus quitoes, proved, unknown to them, a still more certain protection against miasmata." Now this goes clearly to prove, that the safety of these individuals was entirely attributable to the mechanical obstruction afforded by the canvass. It is often noticed by persons with astonishment that one side of a street is the seat of sickness, and not the other:

Clearing land is another fruitful cause. surface of the earth with the vegetable matter, becomes exposed to the action of the sun, and malaria is readily formed; but when the surface of the land is throughly shaded, the agency of the rays of the sun is in a great measure cut off. This circumstance is proved by the fact, that summer residences in pine-land, in most cases, remain healthy, until the officious hand of man destroys the trees, and allows the heat of the sun to act on the land. It is said that it was for this reason that the Romans consecrated their 'groves and woods. Connected with this, is the turning of new land for cultivation in summer, which I think has been almost overlooked. The village of Pineville, which afforded so pleasant and convenient a residence for many families, and now almost entirely deserted, may be cited as an example of the injurious practice of clearing and cultivating land in the vicinity of a summer residence. The following instance is one of much importance, and deserves our attention.

very few cases in the city.

How often do we hear of digging ditches and drains in the summer causing sickness; which fact should show us the propriety of doing such work in the winter. The rich lands of the west, when first cleared and turned for cultivation, if done in summer will cause the deaths of many, which I think has already has been the case. Volney, Rush, M'Culloch, and many eminent writers, have noticed the fact, the breaking up for the first time of meadow land, for cultivation, is always attended with fatal consequences. A writer on the diseases of India, describes the disease produced by this process of cultivation, to be as

fatal as the plague. Laborers residing but one | the difficulty in understanding the language of the night on the spot newly turned in summer, invari- middle and lower classes of people, from whom ably die. he must chiefly derive his knowledge. The rude These causes I think serve in a great measure to dialects in Italy do not vary more in different goaccount for the greater production and propagation vernments, than in the provinces which belong to of malaria in our own country now, than many the same government; insomuch, that a man years ago; for localities once the seat of sickness may have acquired a competent knowledge of the and death, have been rendered prefectly healthy, language in general, and yet be almost an utter by removing the causes of production of malaria, stranger to the terms, and to the jargon, which of which we have spoken. Many situations in are in common use among the peasants. It is Italy and India, may be cited at exemplifying this highly probable, that, notwithstanding my long fact, but let us take an example nearer home. residence in Italy, I have frequently been deceived During my residence in Philadelphia, a few years myself; and, as I should be sorry to deceive ago, different parts of the suburbs of the city were others by pledging the truth of facts which may pointed out to me, as being but a few years pre-admit of doubt, it behooves me to declare, that I vious, as unhealthy as any part of our low country, do not take upon me to write a system of Italian which now is as healthy as any part of that beautiful city. This beneficial change has been effected by draining, filling up, and building, to the entire extinction of bilious fever. Dr. Caldwell, in his treatise on malaria, remarks, "that the large body of land adjoining Philadelphia, on the south, called the Neck, half a century ago, was but little better than a great morass. Nor did the Pontine Marshes surpass it much in the extent and vio- In order to explain myself with clearness and lence of its autumnal diseases. But time and labor precision, which is all that the reader can be prehave converted it into meadows, fields and gar-pared to expect upon a subject of this kind, it will dens, rich in the products of several kinds of cul- be proper to point out the method which I intend tivation. Nor does it flourish more in vegetation to observe. than in health. Its population is now dense. Such is the happy result of draining, banking and planting." I am fully persuaded that our own city may be extended, by pursuing the same process on the neck, which in many places is so liable to fever, owing almost entirely to their being so per-degree affect it; by which, I mean, the nature of fectly neglected, especially as regards draining. Hoping that these remarks may be interesting to many of your readers,

I remain yours, truly,
W. G. RAMSAY, M. D.

agriculture, but only an essay upon it; or rather a series of remarks made upon the spot, and disposed with all the exactness of which I am capable; and, should they not meet with that approbation to which an author naturally aspires, they may, at least, be of use towards inciting others, who have more leisure and experience, to enlarge and improve the design.

I. To examine the physical causes that facilitate or obstruct agriculture; by which are to be understood the rivers and torrents, the soil, the climate, and the general face of the country.

II. To consider the moral causes that in any

the government, the distribution of justice, the modes of taxation, and many other material circumstances that will offer themselves to our discussion under this head.

II. To inquire into the price of labor, the course of crops, the general system relating to manures, and the culture of particular plants; in short, to take a view of what properly constitutes the prac

ON THE EFFECT OF WATER IN THE AGRICUL-tice of the art.
TURE OF ITALY.

By John Symonds, L. L. D. Professor of Modern History in the University of Cambridge.

From the Annals of Agriculture.

IV. To see what inferences may be drawn from the facts above-mentioned, so as to enable us to form a comparison between the ancient and modern agriculture.

Were I to speak of the physical causes which operate upon agriculture in other countries that The favorable reception which my former paper lie out of the neighborhood of high mountains, I has met with among those to whose judgment I should begin with examining the nature of the soil, pay the highest deference, has encouraged me to upon which the quality and value of the produce range in order my observations upon the agricul- almost entirely depend. But the case is different ture of Italy, and to offer the result of them to the with several parts of Italy, where the soil itself public. As the subject of this inquiry has not owes its existence to water, having been formed professedly been treated by any of our voyage-by numberless particles of earth brought down writers, it may fairly be presumed, that the reader from time to time by streams and torrents. Thus, will be disposed to examine it with candor. Every in the Bolognese, one can scarcely dig to the depth man who has investigated the course of husban- of a few feet, without meeting with such kinds of dry in the country in which he resides, must ne-stones as are commonly found in torrents; which cessarily have found himself often embarrassed; naturally leads us to conclude, that the soil has not only on account of the different modes of cul- been brought to its present state by the gradual inture which prevail in different parts, but because crease of successive ages. The same, indeed, the very persons upon whose information he relies, may be observed of the whole plain of Lombardy, are frequently induced to disguise the truth, out of which may properly be called the gift of rivers; crafty and interested views. But, beside these just as Egypt was denominated, in ancient times, circumstances, which are common to the Italians the gift of the Nile. It is also manifest, that the as well as to the English, there is a peculiar ob-vallies in Tuscany have either been entirely formed, stacle with which a foreigner has to struggle, inor greatly altered, by the inundations of rivers and searching into the husbandry of Italy; I mean, torrents. Add to this, that the constant supply of

water, with which a great part of Italy is refreshed | which, the earth, being no longer supported by through the means of artificial canals, does not the roots of the trees, tumbles down in the rivers, only carry with it a considerable addition of earth, together with vast fragments of rocks and marble, but creates, as it were, a new soil every year. and completes the destruction of several rich valHence it appears, that it is necessary to open our lies. We see no where such fatal effects of this inquiries by explaining the effects of water, in practice, as in the territories of Venice. The proorder to ascertain the nature of the soil. I shall duce of the mountains formed a part of the deproceed, therefore, to consider the three following mesnes of that republic, which used either to let particulars: the detriment which has accrued to it at a moderate price, or to distribute it gratuiItaly from streams and torrents; the benefits tously among the inhabitants of the adjacent pawhich it has received from them; and the mis- rishes; and, as long as proper covenants were chiefs which some parts sustain from the want of observed, there was abundance of fine timber, as wholesome water for the common purposes of life. well as excellent fodder for oxen and sheep; but, I. In speaking of the Italian rivers, our first in the last century, the Venetians being distressed thoughts are carried naturally to the Po, which for want of money to continue the war, sold, to inwas celebrated for its rapidity in ancient times; and dividuals, these rights, or beni comunuali, as they which, for some centuries, has been separated into are called, without subjecting them to any restrictwo vast branches; one of which is sub-divided tions, than which, nothing could be more impointo the Primaro and Volarno. Although it swells litic or imprudent; for, as they were allured by the not to a considerable breadth before it receives the profit on the first breaking up of grass-lands, they Tesin, yet it does a great deal of damage within took a few crops of corn in one place, and, as soon twenty miles of its source; insomuch, that the as the soil was washed away, made the like atfarms between Racconigi and Carignano, which tempts in another; so that, in a short time, the are subject to inundations, bear a small value in chief part of the mountains was reduced to culcomparison of others of the same quality in the ture; whence it cannot be wondered, that the neighborhood, that are secure from danger; and Venetians have neither a sufficient quantity of this is the case with most of the estates situated pasturage for their cattle, nor of wood for fuel, and near the Po. Such is the quantity of stones and common utensils, and implements of husbandry. sand that it carries along with it, that when it Monte Baldo, which hangs over the beautiful merely overflows the adjacent lands, the peasants Lago di Garda, and which was once as famous for cannot bring them into a proper state for some timber as medicinal plants, is now entirely naked, years; but, when it breaks its banks, the mischief and exhibits the most dreary sight imaginable. is very extensive; for sallows and willows spring It is difficult, indeed, to determine, whether the reup spontaneously, to the utter exclusion of corn and pasturage, for a long tract of time. We see immense copses of these aquatics on the banks of the Po, through the whole vale of Lombardy; and, in particular, between Tortona and Pavia, and near Broni and Cremona. Yet this inconvenience, great as it is, must necessarily appear trifling, when compared with the terrible effects of the inundations in the lower parts of Lombardy. where some of the most fruitful spots are converted into the most barren marshes.

public has suffered most from the loss of wood and pastures upon the mountains, or from the diminution of corn in the vallies. The Adige, incapable of being controlled, has destroyed above 20,000 acres of the best lands in the Veronese. The Brenta has ruined the vale fom Baffano to Borgo, as well as some of the richest spots of ground in the Padouan. The Piave has laid waste an immense tract of land in the delicious environs of Treviso; and the province of Triuli is desolated by rivers. It is melancholy to see how the plain Although the other rivers in Piemont are not so between Pordenone and Codroipo, near twenty impetuous as the Po, yet, since they rise in the miles in length, is ravaged by the Silo and TagliaAlps, their descent is excessively rapid; and when mento, which bring such heaps of earth and stones they are augmented by accidental torrents, they along with them, that they choke up the very never fail to cover the plains with sand and peb-shallows in the Lagunes. Not many years ago, bles; whence it is that the soil is so ungrateful the republic prohibited, under severe penalties, the from Chivasso to Turin, and likewise to Savigli-cutting down of the wood upon the mountains; ano; insomuch, that the peasants would be re- but the mischief was done, and perhaps, it is irduced to extreme misery, were it not for their reparable. skill in deriving some advantage even from their distresses.

Among the rivers that fall from the Appennines into the Bolognese, the Reno is the most rapid and But beside the losses which the inhabitants sus- dangerous. History affords us few instances of tain from streams and torrents rushing down pre-greater damage occasioned by the diverting of a cipices, there is an additional circumstance which aggravates the misfortune; I mean, the ruinous effects of the cultivation of the mountains. It was the custom of the ancient Romans to set apart the plains for tillage; the hills for vines and olives; and the mountains for wood and pasturage.

Bacchus amat colles, aquilonem et frigora taxi.* The Italians have, in a great measure, reversed this practice, though dictated by good sense and experience; for they have grubbed up the wood, and converted into arable land both the sides and summits of the mountains; in consequence of

* Virg. Geor. 1. 2. v. 113.

river from its proper channel. Clement VIII. removed the Reno from the Po, into which it used to empty itself, with a view of gratifying his new subjects the inhabitants of Ferrara, who wished to avail themselves of that water to improve the valley of St. Martino; but his Holiness's infallihility forsook him upon this occasion, for he did not foresee, that the inundations would destroy a third part of the plain of Bologna. It is generally supposed, that the cities of Ferrara and Bologna

* It was in this river that Colonel Villiers was drowned, which gave occasion to Mr. Prior's beautiful imitation of an ode of Horace.