from being eaten or damaged by caterpillars. 2d. In preventing blights, and their effects on fruit and other trees. 3d, In the preservation of crops of wheat from the yellows, and other destructive insects. 4th. Also in saving crops of turnips from the fly, &c. &c.

1st. Mr. G. was led to his first experiments, by considering how disagreeable and offensive to our olfactory nerves the effluvia emitted by a brush of a brush of green elder leaves are, and thence, reasoning how much more so they must be to those of a butterfly, which may be considered as being as much superior to us in delicacy as inferior in size. Accordingly he took some twigs of young elder, and with them whipped the cabbage plants well, but so gently as not to hurt them, just as the butterflies first appeared; from which time, for these two summers, though the butterflies would hover and flutter round them like gnomes or sylphs, yet he could never see one pitch, nor was there apparently a single caterpillar blown, after the plants were so whipped, though an adjoining bed was infested as usual.

2d. Reflecting on the effects abovementioned, and considering blights as chiefly and generally occasioned by small flies, and minúte insects, whose organs are proportionably finer than the former, he whipped the limbs of a wall plum tree, as high as he could reach; the leaves of which were preserved green, flourishing, and unhurt, while those not 6 inches higher, and thence upwards, were blighted, shrivelled up, and full of worms. Some of these last he afterwards restored by whipping with, and tying up, elder among them. It must be noted that this tree was in full blossom at the time of whipping, which was much too late, as it should have been done once or twice before the blossom appeared. But he concluded from the whole, that if an infusion of elder was made in a tub of water, so that the water might be strongly impregnated with it, and then sprinkled over the tree, by a hand engine, once every week or fortnight, it would effectually answer every purpose that could be wished, without any risk of hurting the blossoms or fruit.

3d. What the farmers call the yellows in wheat, and which they consider as a kind of mildew, is in fact occasioned by a small yellow fly with blue wings, about the size of a gnat. This blows in the ear of the corn, and produces a worm, almost invisible to the naked eye; but being seen through a pocket microscope, it appears a large yellow maggot of the colour and gloss of amber, and is so prolific that Mr. G. distinctly counted 41 living yellow maggots or insects, in the husk of one single grain of wheat, a number sufficient to eat up and destroy the corn in a whole ear. He intended to have tried the following experiment sooner; but the dry hot weather bringing on the corn faster than was expected, it was got and getting into fine blossoms ere he had an opportunity of ordering as he did; but however the next morning at daybreak, two servants took two bushes of ekler, and went one on each side of the ridge from end to end, and so back again,

drawing the elder over the ears of corn of such fields as were not too far advanced in blossoming. Mr. G. conceived, that the disagreeable effluvia of the elder would effectually prevent those flies from pitching their tents in so noxious a situation; nor was he disappointed, for he was firmly persuaded that no flies pitched or blowed on the corn after it had been so struck. But he had the mortification of observing the flies, the evening before it was struck, already on the corn, 6, 7, or 8, on a single ear, so that what damage accrued, was done before the operation took place; for, on examining it last week, he found the corn which had been struck pretty free of the yellows, very much more so than what was not struck. One of those yellow flies laid at least 8 or 10 eggs, of an oblong shape, on his thumb, only while carrying by the wing across 3 or 4 ridges, as appeared on viewing it with a pocket microscope.

4th. Crops of turnips are frequently destroyed, when young, by being bitten by some insects, either flies or fleas; this he flatters himself may be effectually prevented, by having an elder bush spread so as to cover about the breadth of a ridge, and drawn once forward, and backward by a man over the young turnips. He was confirmed in this idea, by having struckan elder bush over a bed of young cauliflower plants, which had begun to be bitten, and would otherwise have been destroyed by those insects; but after that operation it remained untouched. In support of his opinion, Mr. G. mentions the following fact from very credible information, that about 8 or 9 years before, this county was so infested with cock chaffers or oakwebs, that in many parishes they eat every green thing, except elder; nor left a green leaf untouched besides elder bushes, which alone remained green and unhurt, amid the general devastation of so voracious a multitude. On reflecting on these several circumstances, a thought suggested itself to him, whether an elder, now esteemed noxious, and offensive, might not be one day seen planted with, and entwisting its branches among fruit trees, to preserve the fruit from destruction of insects: and whether the same means which produced these several effects, might not be extended to a great variety of other cases, in the preservation of the vegetable kingdom. The dwarf elder (ebulus) he apprehends emits more offensive effluvia, than common elder, therefore must be preferable to it in the several experiments.

XXIV. A Letter from John Call, Esq., to Nevil Mashelyne, F. R. S., Astron. Royal, containing a Sketch of the Signs of the Zodiac, found in a Pagoda, near Cape Comorin, in India. p. 353.

This sketch, fig. 2, pl. 7, Mr. Call drew with a pencil, as he lay on his back resting himself during the heat of the day, in a journey from Madurah to Twinwelly, near Cape Comorin. After such a discovery, he searched in his travels many other pagodas, or choultrys, for similar carvings, but never found above one

more equally complete, which was on the ceiling of a temple, in the middle of a tank before the pagoda of Teppecolum, near Mindurah, of which tank and temple Mr. Ward, painter, in Broad-street, near Carnaby-market, has a drawing; but Mr. Call often met with the several parts in detached pieces.

From the correspondence of the signs of the zodiac which we at present use, and which we had, he believes, from the Arabians or Egyptians, he is apt to think that they originally came from India, and were in use among the Bramins, when Zoroaster and Pythagoras travelled thither, and consequently adopted and used by those travellers: and as these philosophers are still spoken of in India, under the names of Zerdhurst and Pyttagore, he hazards another idea, that the worship of the cow, which still prevails in India, was transplanted from thence to Egypt. But this is only conjecture; and it may with almost equal probability be said, that Zoroaster or Pythagoras carried that worship to India. However, he thinks there is an argument still in favour of India for its antiquity, in point of civilization and cultivation of the arts and sciences; for it is hardly doubted that all these improvements came from the east to the west; and, if we may be allowed to draw any conclusions from the immense buildings now existing, and from the little of the inscriptions, which can be interpreted on several of the choultrys and pagodas, he thinks it may safely be pronounced, that no part of the world has more marks of antiquity for arts, sciences, and civilization, than the peninsula of India, from the Ganges to Cape Comorin; nor is there in the world a finer climate, or face of the country, nor a spot better inhabited, or filled with towns, temples, and villages, than this space is throughout, if China and parts of Europe are excepted.

Mr. Call thinks the carvings on some of the pagodas and choultrys, as well as the grandeur of the work, exceeds any thing executed now, not only for the delicacy of the chissel, but the expence of construction, considering, in many instances, to what distances the component parts were carried, and to what heights raised. Mr. Call also commits to Mr. M.'s inspection the manuscripts of Mr. Robins, which he gave at his death; Mr. C. believes most of them have been printed, but if there are any which have not, or that can amuse or instruct others, you are welcome to use them as you please: I only wish they may contain any thing useful. While he lived, says Mr. C.I pursued those studies; but soon after his death new scenes arose, and engaged me more in practical service, than allowed me time for theory, or experiments.

The sketch, fig. 2, pl. 7, was from the ceiling of a choultry at Verdapettah,

→ These I communicated to the R. s., together with this letter; but being examined by myself, Mr. Raper, Mr. Cavendish, and Mr. Horsley, at the desire of the society, they were not found tocontain any thing material, more than has been already printed; excepting a treatise on military discipline: which, if it should be thought of use, may be inserted in the next edition of his works. N. M.-Orig.

in the Madurah country, taken July 8, 1764. Here A is symbol of the universal deity. BB two hooks of iron, to suspend a kind of throne, on which the deity or swamy often sát, when exhibited to the adorers.

XXV. An Account of the Flowing of the Tides in the South Sea, as observed on board His Majesty's Bark the Endeavour. By Lieut. J. Cook, Commander. P. 357.

Mr. Cook says, that from many circumstances and observations, he is fully convinced that the flood comes from the southward, or rather from the s. E.

XXVI. An Account of a New Electrometer, contrived by Mr. Wm. Henly, and of several Electrical Experiments made by him, in a Letter from Dr. Priestley, F. R. S., to Dr. Franklin, F. R. S. p. 359.

In my history of electricity, and elsewhere, says Dr. P., I have mentioned a good electrometer, as one of the greatest desiderata among practical electricians, to measure both the precise degree of the electrification of any body, and also the exact quantity of a charge before the explosion, with respect to the size of the electrified body, or the jar or battery with which it is connected; as well as to ascertain the moment of time, in which the electricity of a jar changes, when, without making an explosion, it is discharged by giving it a quantity of the contrary electricity. All these purposes are answered, in the most complete manner, by an electrometer of this gentleman's contrivance, a drawing of which I send you along with the following description.

The whole instrument is made of ivory or wood, exhibited in fig. 3, pl. 7, is an exceedingly light rod, with a cork ball at the extremity, made to turn on the centre of a semicircle B, and so as always to keep pretty near its limb, which is graduated: c is the stem that supports it, and may either be fixed to the prime

conductor, or be let into the brass knob of a jar or battery, or set in a stand, to support itself.

The moment that this little apparatus is electrified, the rod A is repelled by the stem c, and consequently begins to move along the graduated edge of the semicircle B; so as to mark with the utmost exactness, the degree in which the prime conductor, &c. is electrified, or the height to which the charge of any jar or battery is advanced; and as the materials of which this little instrument is made, are very imperfect conductors, it will continue in contact with any electrified body, or charged jar, without dissipating any of the electricity.

If it should be found, by trial in the dark, that any part of this instrument contributes to the dissipation of the electric matter, which, when the electrification was very strong, I once observed mine to do, it should be baked* a little, which will presently prevent it. If it be heated too much, it will not receive electricity readily enough; and then the motion of the index will not correspond with sufficient exactness, to the degree in which the body to which it is connected is electrified; but this inconvenience is easily remedied, by moistening the stem and the index, for the semicircle cannot be too dry.

I find by experience, that this electrometer answers all the purposes I have mentioned, with the greatest ease and exactness. I am now sure of the force of any explosion before a discharge of a jar or battery, which I had no better method of guessing at before, than by presenting to them a pair of Mr. Canton's balls, and observing their divergency at a given distance: but the degree of divergency was still to be guessed at by the eye, and the balls can only be applied occasionally; whereas this instrument being constantly fixed to the prime conductor or the battery, shows, without any trouble, the whole progress of the charge; and, remaining in the same situation, the force of different explosions may be ascertained with the utmost exactness before the discharge.

If a jar be loaded with positive electricity, and I want to know the exact time when, by attempting to charge it negatively, it first becomes discharged, I see every step of its approach to this state by the falling of the index; and the moment I want to seize, is the time when it has got into a perpendicular situation, which may be observed, without the least danger of a mistake. Accordingly, I find that, in this case, not the least spark is left in the jar. If I continue the operation, the index, after having gained its perpendicular position, begins to advance again, and thereby shows the exact quantity of the opposite electricity that it has acquired.

Considering the admirable simplicity, as well as the great usefulness of this instrument, it is something surprising that the construction should not have oc

* Warmed a little, to dry off the damps, particularly from the index.-Orig.