CHRONICLES OF SCIENCE.

I. AGRICULTURE.

THE Cattle Plague-which at the beginning of the past quarter was rapidly declining, still however attacking several hundred fresh cases every week-has at length dwindled to very insignificant proportions; and, excepting for its extreme infectiousness, it is no doubt of less account at present than many other fatal disorders to which the live stock of the farm are ordinarily liable. The returns for the weeks ending Sept. 1 and 8 recorded only 99 and 69 attacks respectively in all Great Britain. Upwards of a quarter of a million cases had occurred during the 52 preceding weeks, of which nearly one-half had died and one-third had been slaughtered, leaving, with a certain number unaccounted for, less than one-sixth as the proportion of recoveries. The third and final report of Her Majesty's Commissioners was published in the month of June, and with the accompanying discussions of all the aspects and relations which the subject presents, it constitutes a perfectly exhaustive treatise on the disastrous experience of the past twelvemonth, which all stockowners should study. In particular, the question of disinfection, which it examines, possesses a permanent interest. This has been most elaborately investigated by Mr. Crookes and Dr. Angus Smith, whose researches are given in full detail. The following is the result of their inquiry as stated by the Commissioners :

"It is evident that the poison ought to be destroyed at the very moment of evolution or discharge. The disinfectant must therefore not only be both fixed and volatile, but so cheap and easily used as to be continually in action, and it must of course be innocuous to cattle and men.

"A large number of substances which can be used in many other cases as disinfectants must be put aside, as not meeting these necessary conditions. Compounds of iron, zinc, lead, manganese, arsenic, sodium, lime, or charcoal powder, and many other substances, want the volatile disinfecting power; iodine, bromine, nitrous acid, and some other bodies are too dear, or are entirely volatile, or are injurious to the cattle.

"On full consideration, it appears that the choice must lie between chlorine, ozone, sulphur, and the tar acids (carbolic and cresylic). Two of these bodies, viz. chlorine, in the shape of chloride of lime and the tar acids, have the great advantage of

being both liquid and aeriform; they can be at once added to discharges, and constantly diffused in the air.

"All these four substances-chlorine, ozone, sulphurous acid, and the tar acids-have been practically tested, either in England or on the Continent, and there is considerable evidence that they all actually do destroy the cattle plague poison. Their precise mode of action is still uncertain. Chlorine and ozone act, no doubt, as powerful oxidisers, converting animal poisons into simple and innocuous substances. Sulphurous acid probably destroys the virus by its strong antiseptic powers. The tar acids, according to the experiments of Mr. Crookes, neither interrupt nor accelerate oxidation, but they act most powerfully in arresting all kinds of fermentative and putrefactive changes, and annihilate with the greatest certainty all the lower forms of life.

"After a full consideration of the relative merits of the four disinfectants, and after some practical trials, Mr. Crookes arrived at the conclusion that the most powerful, and at the same time most simple, process of disinfection would be to use the tar acids as constant liquid and aeriform disinfectants, and sulphur in the form of sulphurous acid as an additional and occasional agency.

"For the reason stated in Mr. Crookes's report, it appears that chloride of lime is inferior to the combined use of carbolic and sulphurous acids. But there is no doubt of the efficacy of this agent, and in certain circumstances, as for the washing of railway trucks, it may be employed in addition to boiling water or steam.

"It is very desirable that the use of carbolic acid should become general throughout the country in uninfected as well as in infected districts. There is little doubt that even were there no danger from the cattle plague, the great purifying effect of this substance on the air of cattle sheds would contribute greatly to the health of the animals."

We presume that a very long experience of the use of carbolic acid is necessary before its permanent efficiency can be determined; but in the mean time its cheapness, easy applicability, and power of at once arresting all kinds of putrefactive change, doubtless justify all that the Commissioners say in its favour.

In connection with this subject we have to add that all attempts, arising out of this national calamity, to establish a National Insurance Society and Fund have failed. Dr. Farr, F.R.S., did, indeed, read a paper last June before a meeting of the English Agricultural Society, advocating a plan which he had drawn up, by which the whole live stock of the country might have been insured by Government upon the voluntary principle; but no action followed upon it. To establish such a society, the first thing necessary was that noblemen and gentlemen interested in agriculture should subscribe to a guarantee fund, on the plan adopted at the

Great Exhibition, and it was proposed that Government should subscribe an equivalent amount, engaging to advance money for preliminary expenses at a moderate rate of interest. The guarantee fund was intended only to make advances or loans, and the subscriptions were to be called for by instalments only in cases of necessity. An appeal should be addressed by the Statistical Department of the Privy Council to all the principal stock owners of the kingdom, requesting their concurrence. The concurrent

stock owners would then be requested to send in classified lists of their stock and its value. The premium to be demanded would have to be sufficiently high to cover the risk, and it was believed that 1s. per month would insure 107. on a healthy beast exposed to ordinary risks under good arrangements. No beast worth less than 57. should be insured. The policy might be transferred on the sale of cattle being registered. Horses and sheep might be insured upon terms to be agreed upon. Payment of premiums might be made through the post-office. All payments on policies might be made on the authority of a specially-appointed officer in every county, acting under the inspection of the committee. The accounts should be duly audited and published annually, with a digest of the returns and report made by the actuary, to be appointed by the Home Office. All cattle imported diseased should pay adequate premiums, and if healthy, receive policies covering a term of one month or more; the premium in such cases to be collected by the officers of her Majesty's Customs, and paid by them on account of the Society into the Bank of England. No person having cattle uninsured should under any circumstances receive compensation from any public rate. Landlords, for their own protection, might insist upon the insurance of stock, and clauses might be inserted to that effect in the leases or covenants. Under these encouragements it was probable that half the live stock in the kingdom would be insured. This would give an amount of 2,000,0007. or 3,000,0007., which would be sufficient to cover all losses and expenses, and whatever profits might accrue should be divided among the insured upon the mutual principle.

These were the main features of the plan; but we fear, with Mr. Torr, who followed Dr. Farr at the meeting in question, that nothing of a purely voluntary character has any chance of being taken up by the farmers of the country on a sufficiently large scale to ensure its success. The occurrence of a great calamity of this kind is so new, and has been so rare, that the lesson of selfpreservation which, were it to be of frequent recurrence, it must ultimately teach cannot be expected to be learnt at once.

To turn to the vegetable world, we have in the first place to report the marked success of the Metropolis Sewage Company in growing great crops of Italian rye-grass upon sheer sea-sand.

About 4,000 cubic yards of the sand below Shoeburyness, which is to be the ultimate outfall of the North London sewage culvert, has been spread over an acre of land near Barking. The surface was sown with Italian rye-grass in February last, and the sewage water allowed to trickle over it. Since then several heavy crops have been cut, one of which, grown in a month's time, weighed about ten tons per acre. The efficiency of town sewage, as a feeder of luxuriant vegetable growth, is being tested at other places near the present North London culvert. Mr. Westwood and Mr. Adams, at East Ham, have ten-acre plots which are yielding enormous growths of Italian rye-grass; and at Lodge Farm, near Barking, the Sewage Company are laying down a large extent of land for surface irrigation, so that in a year or two we may hope to see all South Essex convinced of the enormous fertilizing power which is about to be distributed through that district.

The weather of the past summer has been more favourable for succulent growth, such as that of Italian ryegrass, than for the ripening of seeds, and thus we have to report unfavourably of the harvest. A large proportion of recently published reports of the wheat crop declare it to be below an average, and the extremely wet weather of September has much injured grain crops in the later districts.

One other matter of some agricultural interest may be referred to in this Chronicle. The National Agricultural Societies, both in England and Scotland, are trying by means of paid commissions to ascertain with accuracy the experience of farmers in steam cultivation. As the sum of one thousand pounds has been voted for the purpose by the English Society, we may hope soon to have a full report of the costs and difficulties, advantages and returns, which have been hitherto experienced in connection with the various methods by which steam power has of late been applied to the cultivation of the land.

II. ASTRONOMY.

(Including the Proceedings of the Royal Astronomical Society.) DURING the last few years very close attention has been bestowed by some of our best observers upon the details of the solar surface. The appearance and behaviour of the objects called willow-leaves, by Nasmyth, have been observed with especially attentive scrutiny. The variety of names applied to these objects, which have been called rice-grains by Stone, crystals by Chacornac, shingle-beach by Brodie, coups-de-pinceau by Secchi, and corrugations or bright

nodules by Sir W. Herschel, is sufficient to indicate the propriety of the less distinctive name granules selected by Messrs. Dawes and Huggins. Hitherto observation has chiefly been confined to the appearance of the granules on those parts of the sun in which the influence of disturbing forces is apparent, as in the areas of the spots. In these regions only is it that the objects assume that lengthened form from which has been derived the comparison to straws or willow-leaves; and here only, if anywhere, do they present the appearance of interlacing, which has been compared by some observers to thatching.

In a paper referred to in the last Chronicle, Mr. Huggins presented the results of some observations of the bright granules on those parts of the sun which are free from spots.

The granules are to be observed over the whole surface of the sun excepting the areas containing spots, and they may be seen occasionally unchanged from their normal figures in the penumbræ and umbræ of spots. Observed with powers of about 100 diameters they present an appearance aptly described by Mr. Stone's epithet rice-grains; but when higher powers are applied the granules present less regularity of figure and size. Besides oval and nearly round granules, irregular masses may be observed. The granules do not appear to be flat discs, but bodies of considerable thickness.

These bodies would appear to average about 500 miles in breadth, and from 500 to 600 miles in length; some however are smaller, and occasionally a granule some 1,000 or 1,200 miles in diameter may be seen. Their distribution over the solar surface is very singular. On many parts of the sun they lie in groups, the components of which are separated by small intervals. These groups vary in form, in some places being round or oval cloudlike masses (mistaken probably for single granules by some observers); elsewhere they are long irregularly formed bands. On one occasion Mr. Huggins observed near the centre of the sun's disc "a long oval border of tesselated bright matter, enclosing an area over which the granules were sparsely distributed." To such groups, and to the varying brightness of the material between groups and granules, the coarse mottling of the solar surface visible when the sun is observed with low powers is to be attributed. Mr. Huggins considers that, except in the penumbræ of spots, the granules are not superposed on each other as long as they remain separately recognizable.

What are these bright bodies? Are they, as their appearance suggests, recently condensed incandescent clouds, or, as Mr. Dawes considers them, merely "ridges, waves, hills, or knolls (or whatever else they might be called)" on the surface of comparatively large luminous clouds ? Whence, also, "the general approximate