kind is indicated by any observations last night, though a few of the meteor tracks (perhaps five or six in all) would not pass strictly through the radiant if traced back. C. A. YOUNG.

Princeton, N.J., Nov. 28.

A bright meteor.

On Friday, Nov. 13, about 10.30 A.M, the attention of a number of our students was attracted by a brilliant meteor.

The appearance as described by Mr. H. Toulmin, of the senior class, is as follows: The path of the meteor began 15 or 20° west and north of the zenith, following a north-westerly direction, and ending some 20° from the horizon.

The brightness he compares to that of Venus when seen at night. The sun was shining brightly, and no clouds were noticed. No explosion was heard, nor did any fragments seem to reach the ground. C. L. DOOLITTLE.

Lehigh university.

Absorption of mercurial vapor by soils. Last year considerable attention was excited by the proposition to utilize the insecticide properties of mercurial vapor against the phylloxera or vine-louse. This suggestion originated with Mr. J. A. Bauer, a druggist of San Francisco, and himself the owner of a vineyard in the infested region of the Napa valley, where he had for some years experimented on the efficacy of mercury, and satisfied himself of its usefulness as a preventive of infection, when, in planting, each cutting was surrounded by a few inches of earth mixed with 'deadened' mercury. Upon publication of the fact, a considerable demand for the mercurial mixture (consisting of equal parts of finely divided mercury and clay or chalk) was made by persons interested, and many thousand vines were treated in different localities in the manner prescribed by Mr. Bauer. This was to mix thoroughly about a peck of earth with an ounce of the above mixture, and fill in with it the hole in which the cutting has been placed, to the depth of at least six inches from the surface. Many experiments were also made on vines already infested, to see if the mercury would gradually spread so as to disinfect the whole of the root system.

Contrary to expectation, most of these experiments proved a failure, inasmuch as the phylloxera seemed to continue, unchecked, on the roots already infested, and in some cases clean cuttings had become infested, despite the surrounding mercurialized soil.

Having witnessed a number of the successful experiments upon which Mr. Bauer's recommendations were based, I undertook an investigation of the circumstances of the reported failures, and soon discovered two that were essential. One was that the mercury used was considerably contaminated with lead, which is known to diminish exceedingly the evaporation of mercury; another, that oil had been used in order to facilitate the deadening' process, and thus each globule was covered with a film that additionally impeded volatilization. In fact, the iodine test for mercurial vapor showed that a mere trace of the latter existed around the mixture furnished by Mr. Bauer, while a similar one prepared with pure mercury showed abundant volatilization at the ordinary temperature, and acted very promptly upon insects.

Yet, upon using the latter mixture in the manner prescribed by Mr. Bauer, in a very clayey soil, neither the insects nor the iodine test manifested the presence of mercurial vapor. It was now remembered that Mr. Bauer's successful experiments had been made in a very sandy soil of the city of San Francisco; and the inference was plain, that, just as aqueous vapor would be absorbed to a much greater extent by a clay soil than by sand, so the mercurial vapor was at first absorbed by the former until saturation was reached, which might not be for many weeks or even months; the soil acting as an effectual disinfectant until supersaturated.

Experiments proved this surmise to be correct; and the investigation, still in progress, seems to show that the capacity of soils for the absorption of aqueous vapor may serve as an approximate measure of their relative capacity for the absorption of mercurial vapor also. Thus in pure sand, which in a saturated atmosphere at 15° C. absorbed only .5 per cent of aqueous vapor, the amount of mercurial vapor absorbed was too small for analytical determination; while in a clay soil, absorbing, under the same conditions, 6 per cent of watery vapor, the mercurial vapor retained at 49° C. amounted to .012 per cent, equivalent to about 130 grains per cubic foot of soil. Now, since from one-fourth to one-half cubic foot was used in the treatment of vines, it follows that from 33 to 65 grains of metal out of the 240 used in each case, would have to evaporate and impregnate the soil, before any free vapor would be available for action on the insects. At the low temperature of the soil this would naturally take a considerable length of time: hence the failures.

It is of course perfectly feasible to insure this impregnation beforehand by exposing the mercurialized soil to a higher temperature (e.g., to that of 49° C., easily attained in California by exposure to the sun) for ten or twelve hours, or for a much shorter time to steam-heat. A clay soil so prepared will act on the phylloxera as promptly as when sand is used; all being dead, or incurably poisoned, within from 20 to 30 hours.

The method is therefore far from being a failure, as has been industriously represented by interested parties. It will accomplish all that has ever been claimed for it; to wit, the preservation of young vineyards from infection through the ingress of the phylloxera from above; and, as there is no occasion for disturbing the earth immediately surrounding the stock of a vine, there is no reason why this protection should not continue for all the time the vine is likely to live. With proper precautions, it will also, no doubt, be available against other insect pests of similar habits; e g., the woolly aphis' (Schizoneura lanicera Hausm.) The conditions for successful application in practice in various cases are still under investigation. E. W. HILGARD. Agric. exper. station, Berkeley, Cal., Nov. 23.

The English sparrow.

Your correspondent in Science, No. 147, asks for information in regard to the English sparrows. In this city (Cincinnati) and vicinity there are large numbers of these birds, and local ornithologists have no hesitation in saying they drive away the native songsters.

At my house, in one of the thinly populated suburbs,

they were abundant during the summer. A patch of woods close by harbored many native birds which occasionally strayed into trees near the house. As soon as one of these ventured to alight on a branch, the sparrows would desert the eaves of the house and settle on the tree, and there they would chirp and chatter till the other bird was literally driven away. Robins and flickers were greatly annoyed, but the cat-bird flirted his tail in disdain, and seemed to be the only one which could not be driven away.

As for their insectivorous habits, I have been informed by Mr. Charles Dury that he has dissected forty or fifty of the birds which were shot at different times and places during two years. In none of these, with but a solitary exception, did he find a trace of the remains of an insect. Every one was filled with seeds of one sort or another; and he concluded the insect had been picked up and swallowed by mistake. Still, it would appear that numbers of cicadas were killed, though not eaten by the birds, here as well as in Washington.

As far as the extermination of the sparrow goes, it does not seem a difficult task. Let the laws protecting it be repealed. Let a bounty be offered for every scalp, and free permission to kill whenever and wherever found would tend to rapidly diminish the number of the pests. The increase in number is largely due to the protection afforded by law, and by the sentiment of people. If wolves, bears, and panthers can be exterminated by the means above spoken of, there seems little reason to say that the same result would not follow with the sparrow. Cincinnati, Nov. 27.

Jos. F. JAMES.

I would like to give some information in regard to the habits of the English sparrows, which I hope will soon be stamped as outlaws, and a price put on their heads, like unto those of all marauders.

They not only drive away our native birds, but are the worst enemies of the fruit-grower and gardener. They are not scavengers, but, on the contrary, by their habits become defilers of human dwellings and water. I will give such facts as came to my notice during many years of observation at my home in Hudson county, N.J., which will substantiate the above assertions.

We had provided numerous boxes for nests for bluebirds and wrens in the trees, and before the introduction of the English sparrows in New York, in 1864, these were invariably occupied by the same family each spring: additional nests were always soon occupied. Any one acquainted with these pretty little singers will understand the peculiar charm they lend to a country home. During the summer-time the grove would be full of thrushes, who would build their nests in the underbrush, and fill the morning and evening air with their melodious song.

Within four years after the introduction of English sparrows, they had found their way to our home, and immediately began harassing the bluebirds, sometimes destroying their nests. As soon as we noticed this, we took the part of our pets the bluebirds, and would fight the sparrows at every point. This was soon noticed by the bluebirds; and it actually happened, that, when hard pressed by the sparrows, they would fly close to the house, to attract our attention to their trouble by plaintive cries. We succeeded in

protecting them for a few years; but, with the rapid increase of the sparrows, the bluebirds have left their former abodes, never to return to them except as travellers.

When we noticed that the wrens were harassed in a similar manner, we made the entrance holes to the boxes so small that sparrows could no longer enter. We then found that the sparrows would take turns about sitting on the perch in front of the opening until the old wrens had left, or until the young ones were starved. In two cases we found that old wrens had been kept imprisoned until starved to death by the sparrows preventing their exit. We did all we could to drive them off, - shot them with guns, caught them in traps, destroyed their nests, etc.; but all in vain. They learned to recognize a gun, and, as they always have guards in a flock, a signal from a guard would scatter them to the winds instantly. They could only be caught in traps for but a short time, when again they would become acquainted with them, and avoid them. The best way to drive them away seems to be to destroy their nests without tiring; then they will partly leave. They would fight the brown thrush, and scatter its eggs, whenever opportunity presented itself, and seemed to take particular delight in pulling the nests to pieces to build their own with the debris.

In spring they destroy the strawberries, to begin with, and attack every variety of fruit, except currants, gooseberries, and apples. They do not feed on cherries to make their living, like native birds, but merely take a bite of each berry, and destroy it wantonly. When pears are ripe, they will peck large holes in them to drink the juice. They generally appropriate half our vineyard, and cannot be frightened by scarecrows. They invariably keep themselves busy, when not hungry, by picking off young sprouts, especially of fine plants and rose-bushes, but do not spare trees. It seems that they do this merely to keep themselves busy. In addition to the above, they do not destroy worms which build a web, although they probably destroy chrysalides or open cocoons in winter-time, when they can find no other food. We have never seen them destroy worms in summer-time, when other food is abundant.

FRIDAY, DECEMBER 4, 1885.

ELECTIVE STUDIES AT HARVARD.1

A NEW departure has been made in Harvard college during the past year, in that, for the first time in its history, freshmen have been allowed to choose a majority of their studies. Under the new rules but seven-sixteenths of the work of the freshman year will be prescribed: the rest of the college course, excepting a few exercises in English composition, will be elective.

Let us examine on what facts the Harvard faculty build their confidence in the elective system; in what sense it can be called a system; whether, furthermore, its introduction, while making instruction more agreeable, does not tend to lower its standard; and, last, whether its tendency is to foster character, and to make vigorous and law-revering men.

A preliminary objection is that the so-called system is really no system at all, but a mere cutting of straps. This is a misconception. The student under it merely chooses the specific topic of his study: what the amount of it shall be, and what its grade of excellence, are decided for him. After completing his freshman year, the Harvard student must pass successfully four elective courses in each of the following three years; and in each course or single line of study 50 per cent of a maximum mark are required each year for a pass. After his first year, then, the Harvard B.A. must have prosecuted twelve courses of self-selected studies, and mastered them at least half perfectly.

The essence, then, of the elective system, is fixed quantity and quality of study, but variable topic. Every important New England college admits it, to a certain extent, in both senior and junior years, while some allow it in the sophomore. In Harvard its adoption has been very gradual. In 1825 options were first allowed in modern languages. Years of experiment followed, with the result that the old method was step by step abandoned. The time of transition has been one of great prosperity. During the past fifteen years the gifts to the university have averaged $250,000 a year, and the number of students has steadily increased; the average attendance of undergraduates during the five-year period 1861 to 1865 amounting to

1 Abstract of Professor Palmer's article on Elective studies at Harvard university, Andover review.

only 423, while that during 1881 to 1885 reached a total of 873.

Harvard, then, has become prosperous by taking the lead in a great educational movement, the necessity for which lay in the fact that of late years the field of knowledge has so greatly widened. A place on the college curriculum has had to be found for modern languages, political economy, and science in its various departments. To avoid the danger of superficiality, — which is opposed to thorough-going discipline and the acquirement of sound mental habits of thought, a choice was necessary between so many different subjects. In making this, too, personal aptitudes had to be considered, and thus a new principle was introduced; viz., that of valuing studies less according to their subject-matter than according to their fitness for the mind of the student. The will came to be treated as of primary importance. The student is told at Harvard, 'Study what you will, but you must will to study something.' The boy is thus taught how to choose during the formative period of his life, that is, between the ages of eighteen and twenty-two.

A manlier type of character is actually observed as the elective principle extends. The students show an enthusiasm for their work that was lacking formerly. Their ideal of a 'gentleman' is now higher than it was; and hazing, windowsmashing, and disturbing a lecture-room, are now things of the past. That a decent scholarship has now become reputable, may be seen from the fact that in the last senior year 91 out of 191 men received honorable mention;' i.e., took a high rank in three or more courses of a single department. The following table, which gives the average percentage of marks attained at examinations during the past ten years shows that the standard of good scholarship has been steadily rising.

prescribed studies gained less than 60 per cent, ten years later one-half of the seniors obtained four-fifths of a perfect mark in four electives.

Two objections may here be raised; viz., that the selected courses will have but little connection with each other, and that the easiest ones will always be the favorites. An answer to the first objection is contained in the fact that nearly one-half of the last senior class chose at least three closely related courses. The charge of 'soft' courses is the stock objection to the elective system, and seems, a priori, a sound one. The subjoined list of the courses which in 1883-84 were most largely attended by seniors and juniors, shows that, when choice gets full play, the factor of interest may make a severe study popular.

The courses were: Mill's political economy, 125 seniors and juniors; later European history, 102; history of ancient art, 80; comparative zoology, 58; political and constitutional history of the United States, 56; psychology, 52; geology, 47; constitutional government of England and the United States, 45. Are not these studies just those which should be the most popular?

It may be asked how such wise selections are secured, and we answer, simply by making them deliberate. In June the students must choose their studies for the next year, and notify the dean of their choice. Until Sept. 21, any elective may be changed, on notice sent to the dean. During the first ten days of the term no changes are allowed, but afterwards for a short time they are easily effected. For the remainder of the year no change is possible, except for urgent reasons.

By these means the faculty tries to avoid waste of time over unprofitable studies. Of course, not seldom unwise choices are made; but is not that true to an even greater extent in the case of prescribed studies? Moreover, the wastes of prescription affect chiefly the energetic and original students, while under the elective system it is especially the shiftless and dull who suffer, that is, men who cannot be much harmed by any system.

Then, how much the instruction under the two systems differs! When studies are prescribed, the teaching becomes often a secondary affair, and the pupils have to be urged to work. Under the elective system the student feels that he has something at stake, and a higher style of teaching becomes possible. Theses are read, and original works consulted. During 1860-61 only 56 per cent of the Harvard undergraduates consulted the college library; during 1883–84, 85 per cent.

Then, again, under the new system at Harvard, attendance at lectures is not compulsory; though, of course, a lengthened absence would

not be permitted. The results obtained from trusting the students have been satisfactory. In the last senior class the total absences, whether from sickness, misdeeds, or other causes, amounted to but 16 per cent of the total number of recitations. Colleges requiring attendance seldom show better results.

But when studies are elective, professors are benefited equally with students. Teacher and taught are brought closer together, a common sympathy animating both alike. The professor, too, gets to see himself as others see him, and, if inefficient, his class soon dwindles away. Both professors and students are, in fact, put on their good behavior.

But why introduce the elective system so early as the freshman year? First, because the youth of eighteen needs just such a happy influence on his character as the system gives; second, because the loss of time incident to learning to choose can best be borne in the earlier, that is, least valuable, college years; while, last, the change from school to character methods is too important to be marked by the mere passage from one class to another. A change of residence should mark it. A character-college, then, while no place for the indolent rich, is best suited for the democratic many, to whom the elective system gives an opportunity for mental and moral expansion which no compulsory system can afford.

We must, however, remind the reader that the system is not yet perfected, and has still many imperfections. Convinced, as we are, of the soundness of its method, we invite criticism, which should now turn to the important work of bettering its details of operation.

ENSILAGE IN ENGLAND.

IN a return to the house of commons, entitled 'Ensilage commission, evidence, part i., Preliminary report and minutes of evidence,' and in a 'Return of the replies to questions relating to silos and ensilage put by the agricultural department, privy council,' which have lately reached us, the latest information is contained in regard to the views held in Great Britain as to the value of silos and ensilage, and the practical successes and experiences with this still somewhat experimental method of preserving and feeding various kinds of green food to stock, in an undried condition.

The evidence obtained voluntarily by the parliamentary commission from thirty-eight witnesses, including Sir John B. Lawes, Viscount De Chezelles, and the owners and occupants of many large estates, their agents and tenants, and the inventors of different forms of silos, not excluding

any testimony of an unfavorable nature, but endeavoring to induce persons believed to be opposed to the system to give their opinion, has in their opinion, without exception, established the claims of the system to a considerable amount of success ; and, although in some cases the results have been evidently more satisfactory than in others, nevertheless, all the systems seem to show that a nourishing, useful food for animals can be preserved, independently of any drying process, within wide lines of divergence in the details of the methods adopted. Different degrees of weighting and of exclusion of atmospheric air are the causes of different degrees of heat, and of consequent chemical change produced. It is apparently, as yet, largely a matter of opinion whether such chemical changes increase or diminish the feeding value of the ensilage, or its relative value in comparison to the green crop. The solution of this question the commissioners naturally regard as of great importance, and consider that careful feeding experiments, conducted with a view to test the exact effect of these changes, are very desirable. They find that whether the ensilage has been covered in immediately after cutting, or put in at intervals, the air not being immediately excluded and considerable heat developed, yet in both cases a useful feeding material has been obtained which would have been lost if any attempt had been made to convert it to hay in unfavorable weather.

As to the economy of different systems of making and storing ensilage, the commission is not prepared to express an opinion; nor does it desire at present to compare the advantages of different systems, the quality of the ensilage being not materially affected thereby. Special circumstances affecting particular localities must influence and regulate the methods employed. It was found that some of the best ensilage was produced with a pressure of not more than seventy pounds per square foot, but the degree to which weighting is necessary or desirable remains to be decided. Good results are claimed with weights between seven and three hundred pounds. Evidence shows that all differences in actual results, not dependent on composition of food-plants employed, are traceable to the variations in the degree to which fermentation is allowed to be set up in the silo, and the length of time it is continued. The fermentation, too, is controlled by or dependent on the manner of constructing, filling, covering, and weighting.

The testimony of the dairy farmers does not appear to justify the assertion, which has been more or less circulated, that dairy products are affected by ensilage; on the contrary, there is

much valuable evidence to show that well-made ensilage distinctly improves the yield of milk and cream, and the quality of the butter. This is of interest on this side of the water, as a similar report has gained ground here, without, as far as has been learned from our investigations, any reason, unless the ensilage is fed too soon after coming from the silo. It should be exposed, at least in the case of sour maize ensilage, for a period of twenty-four hours to remove an odor which sometimes affects the milk when the feed is fresh. Tainting of the milk, the commission considers to have been due in many cases to proximity to strong-smelling ensilage after milking. The report concludes by saying that they have heard sufficient evidence to warrant the extension and development of the system as a valuable auxiliary to the farm.

The second part of the report of the commission, soon to appear, will contain the documentary evidence obtained in answer to twenty-five practical questions sent to the proprietors of silos in various parts of the kingdom. We have before us the answers to similar questions sent out by the agricultural department, privy council, which have been published in the second report which has been alluded to, in much the same way as was done by the U. S. department of agriculture two years ago. From the summary of the replies, we learn that the silos in Great Britain have doubled in number in the space of twelve months, that they vary in capacity from 96 to 55,440 cubic feet, averaging 2,801, and that they are built both with and without provision for drainage, but largely without. Drainage, it is suggested, requires care to prevent admission of air, and, we would add, loss of nutrients when the pressure is not properly regulated. The construction of the silos varies in material and location according to the locality where they are built. Any material furnishing the absolute requisite of rendering the walls air-tight seems suitable and successful, and localities where there is sufficient difference to enable the filling to be done at one level, and the drawing-out at a lower one, seem to be most favorable. Oats, green barley and wheat, maize, buckwheat, sanfoin, rye and all sorts of grasses, hop-vine, turnip tops, peas and beans, with mowings from hedges, and fences, and ditches, including nettles, sedges, and rushes, have all been more or less successfully made into palatable ensilage. The addition of salt was mentioned unfavorably in many reports, as was the case with the testimony before the parliamentary commission. The methods of compression have varied very much, but dead weight has been largely employed, and water-tanks so arranged as to be air