"which in their larva or maggot 66 "the leaf, and have more the ap pearance of filaments of flowers "with their antheræ, than the eggs "of an animal. The number of "these insects being comparatively "small, they may be considered "rather as the casual invaders of "of their destroyers. The earwig. "which is itself no contemptible 66 enemy to plants, makes some atonement for its depredations, by "destroying the aphides, especially "such as reside in the curled-up "leaves of fruit trees, and the 66 purses formed by certain aphides 66 state, feed on such a variety of "food as the musca, or fly. There "is scarcely a part of nature, "either animate or inanimate, in "which they are not to be met << with. One division of them, called by Linnæus muscæ aphidi-"their existence, than the main host "vora, feeds entirely on aphides. "Of the different species of aphidi "vorous flies, which are numerous, "having mostly bodies variegated "with transverse stripes, their fe"males may be seen hovering over "plants infested with aphides, among which they deposit their eggs on "the surface of the leaf. The lar66 va or maggot produced from such 66 eggs, feeds, as soon as hatched, on the younger kinds of aphis, " and as it increases in size, attacks "and devours those which are lar<< ger. These larvæ are usually of 66 a pale colour, adhere closely to the leaf, along which they slowly "glide, and are formed very taper. "ing towards the head. When fully grown, they change to a pupa or "chrysalis, attached to the leaf, "from whence issues the fly. The "larvæ of these flies, contribute "their full share to diminish the "despoilers of Flora. To these "three kinds of insects, which are "the chief agents in the hands of "nature for keeping the aphides " within their proper limits, we may "add a few others, which act a "subordinate part in this neces 66 sary business of destruction. The "larva of the hemerobius feeds on "them in the same manner as that "of the musca aphidivora, and de"posits its eggs also on the leaves of such plants as are beset with "aphides. The eggs of this heme"robius stand on long filaments, "which are attached by a base to 66 on the poplars and other trees, "Lastly, we may add as the ene "mies of these creatures, some of "the smaller soft-billed birds, which "generally feed on insects, and "which may be frequently seen "busily employed in picking them " from the plants." "When plants assume a sickly appearance, or are disguised by disease, from whatever cause "the disease may arise, they are "said to be blighted. Blights ori "ginate from a variety of causes, "the chief of which are unfortunate "weather, and insects. Two op "nions prevail very generally in "regard to blights; the one, that the insects which cause them, are brought from a distance by easter ly winds; the other, that they "attach themselves to none but #blights. Other insects it is true, more especially the larvæ of some "of the lepidoptera, as those of the "being arrived at maturity at the same moment of time. Detaching "itself from the plant, each pursues phalcene torti ices, disfigure and do a differentroute,intent on the great ؟ business of multiplying its species; and settles on such plants in the vicinity as are calculated to afford nourishment to its young. The common green aphis, which is so generally destructive, lives during ،، the winter season on such herba ceous plants as it remained, on "during the autumn, either in its If the wea ، .fill a volume with observations, egg or perfect state ؛ "females of these insects acquire "wings; and thus the business of "increase, hitherto confined, is to which I have been an eye-wit-ther be mild, it multiplies greatly ness, of the injuries which plants" on such herbage; as the spring "sustain from insects; but that "advances, in May, the males and "would be foreign to my present "purpose, which is to shew that the "aphis is the grand cause of these "diseases, and to place the modus "operandi or manner in which they "effect this business, in its true light.” "We are fully aware that certain "gregarious insects may, at parti"cular times, rise up in the air,and if 66 small and light, be impelled by any "wind that may chance to blow at "the time; and on this principle "we account for that shower of "aphides described by Mr. White "to have fallen at Selborne. But "certainly this is not the mode in "which those insects are usually "dispersed over a country, the “ phenomenon is too unusual, the "distribution would be too partial; "for the aphides, while at their "highest point of multiplication, do "not swarm like bees or ants, and "fly off in large bodies; but each "male or female aphis, at such pe "riods as they arrive at maturity, ، marches or flies off without wait"ing for any other. Yet it may "happen, that from a tree or plant thickly beset with them, numbers may fly off, or emigrate together, 66 widely and rapidly extended, as "the winged aphides, by hop-plant،، ers called the fly, may be seen at this period very generally sitting "on plants, and floating in the air, in all directions." Mr. Curtis, in the preceding observations on the genus aphis, having mentioned the shower of aphides recorded by Mr. White, it cannot but be agreeable to the reader to be made acquainted with so curious a phenomenon, in the words of its describer. "As we have remarked above, “ that insects are often conveyed "from one country to another, iù " a very unaccountable manner, I shall here mention an emigration ،، of small aphides, which was ob. served in the village of Selborne, "were walking in the streets at that 66 juncture found themselves cover"ed with these insects, which settled "also on the hedges and gardens, blackening all the vegetables where. they alighted. My annuals were discoloured with them, and the "stalks of a bed of onions were quite coated over for six days "after. These armies were then no doubt in a state of emigration, 66 "and shifting their quarters; and "might have come, as far as we "know, from the great hop-plan"tations of Kent or Sussex, the "wind being all that day in the eas"terly quarter. They were ob "served at the same time in great "clouds about Farnham, and all "along the vale from Farnham to "Alton." USEFUL USEFUL PROJECTS. List of Patents for new Inventions, &c. granted in the year 1805. ED 'DWARD Shorter, of New Crane, Wapping, in the county of Middlesex, mechanic; for a mechanical apparatus, by which the raising of ballast is rendered more easy, cheap, and expeditious, and which may also be applied to other useful purposes. Dated January 16. William Lester, of Piccadilly, in the county of Middlesex, engineer; for an improvement on an engine or machine for separating corn, seeds, and pulse, from the straw. January 16. Dated Samuel Chifney, of Newmarket, in the county of Suffolk, rider; for improvements upon bitts of bridles. Dated January 16. Thomas Hamilton Keddie, of Duke street, Grosvenor-square, in the county of Middlesex, sadler; for a cartouche-box, or receptacle for cartridges of gunpowder, or gunpowder and ball, for charging musquetry or artillery, or any other description of fire arms. Dated January 19. Edward Thunder, of Brighthelmstone, in the county of Sussex, gentleman; for an improved mode or method of keeping in tune certain musical instruments called pianofortes, grand piano-fortes, harpsichords, spinnets, and other stringed instruments. Dated January 23. John Robert Lucas, of Charltonhouse, in the county of Somerset, esquire; for an improvement in the art or method of making, spreading, or flattening sheet glass, or any other spread glass requiring a polished surface. Dated January 23. John Jones, of the city of Chester, chemist, for a liquor for printing and dying of cotton, linen, and woollen. Dated January, 23. Frederick Mollerston, of Hackney-wick, in the county of Middlesex, gentleman; for a chemical composition, and method of applying the same, in the preparation of hides, skins, and leather; silks, taffetas, and linen, and to all articles already made of skins and leather, thereby colouring and giving a beautiful gloss to the same, rendering them water-proof and impenetrable to hot or corroding liquids, and at the same time preserving them from decay, and keeping them soft and pliable. Dated January 23. Simeon Thompson, of Redcrosswharf, upper Thames-strect, in the city of London, coal merchant; for a bushel or bushels, and other measures, upon a new construction, for measuring coals, grain, seed, and other dry measurable commodities. Dated January 23. James Barrett, of Saffron Walden, in the county of Essex, smith and iron-monger; for an improvement in the construction of maltkilns, so as to prevent damage from fire, and to save fuel in the drying of malt. Dated January 29. John Heppenstall, of Doncaster, in the county of York, machinemaker and engineer; for improve ments in slivering and preparing hemp, flax, and substitutes for hemp and flax, previous to the operation of spinning. Dated February 5. William Hackwood the younger, of Shelton, in the county of Stafford, potter; for a method of making windows and lights upon new prin. ciples. Dated February 5, 5. John Ball, of the city of Norwich, engineer; for a machine for threshing corn and pulse. Dated February 5. James Fullarton, surgeon in the navy; for a diving-machine, or apparatus, upon an improved construction, applicable to various useful purposes. Dated February 5. Christopher Perkins, of Stockton, in the county of Durham, builder; for a machine for threshing corn and pulse. Dated February 5. James Ryan of Doonane, in the Queen's county, Ireland, engineer to the undertakers of the grand canal; for sundry tools, implements, or apparatus for boreing the earth for coal, and all kinds of minerals and subterraneous substances, by which the different strata may be cut out in a cheap and expeditious manner, in cores or cylinders, from one inch to twenty inches and up wards in length, and from two inches to twenty inches and upwards in diameter, so as to be taken up entire at any depth that has hitherto been bored; by which, not only the quality of such minerals and substances, but also the declination or dip of the strata can be ascer. tained beyond a possibility of mis. take; and which tools, implements, or apparatus are also advantageously applicable to the purpose of sink. ing for wells, and giving vent to subterraneous water in bogs, and draining mines and grounds, and ventilating pits and other beneficial purposes. Dated February 12. Charles Coe, of the parish of St. Mary, Whitechapel, in the county of Middlesex, baker; for a flue upon an improved construction, ap plicable to the heating of ovens, or any other thing that requires an uniform heat. Dated February 12. William Martin, of Houghton Pans, in the county of Northum berland, rope-maker; for a mode of fastening shoes to the feet of men, women, and children. Dated February 19. George Dodd, of Great Ormond, street, in the county of Middlesex, engineer; for improvements on the royal York gun-lock, other gunlocks, and the locks of all description of fire arms. Dated February 28. John Robert Irving, of the city of Edinburgh, advocate, and Isabell Lovi, of the city of Edinburgh afore. said, worker in glass; for an improved apparatus for determining the specific gravity of fluid bodies, and the relation that their weight bears to a given measure. Dated March 9. John Baptiste Denire, of Weststreet, Somers-town, in the county |