atively small amounts required. There is one mineral element which may be said to be the pabulum par excellence of growing fruits, and that is potash. It is certainly true that we cannot raise perfect and desirable fruits if we withhold this element from the soils of our orchards. When it is considered that we influence growing fruits only through the act of rendering the tree or vine vigorous and healthy, and when we further consider how much potash is required to maintain a normal condition in large fruit-trees, which are constantly under the pruning-saw and knife, we obtain some correct views of the importance of this agent in soils. Both the fruit of the vine, and the vine itself, are great consumers of potash. The same may be said of most of our small or soft fruits.

It is not usually advisable to attempt to reclaim and render productive a worn-out grape border; but if any satisfactory success is attainable, it is only through a plentiful supply of good wood ashes and bone meal.

Twenty years ago I discovered that it was best, in preparing borders for cold grape-houses, to use plenty of wood ashes, and to place the fertilizing materials in successive thin layers, rather than in the usual form of a mixed heap. I have one border prepared in this way which is made up of sixty alternating strata of different fertilizing substances, and they have remained undisturbed for twenty years. The fruit product from this border has been uniformly excellent in quantity and quality, from year to year, and renewal has not been necessary.

My view is, that the subterranean feeders of the vine will follow what may be designated as vegetable instinct in procuring food, going no further for it than is necessary. If we place phosphoric acid, lime, potash, and nitrogenous salts in distinct layers, each resting upon one of good soil, we place our vine roots, as it were, at a table spread with many dishes, and unerring instinct will guide in selecting what is needed to keep the vine and fruit in the best possible condition.

The saccharine qualities of the Black Hamburg and Frontignan varieties are greatly improved by having at hand plentiful supplies of potash; and wood ashes is the best possible source for this alkali. The German chlorides are next to be preferred, but do not, in vineyards, meet the desirable results supplied by ashes.

The ordinary German kainit, as found in commerce, I class among the poisons in the list of assumed vegetable foods. I have never failed to observe injurious results in the use of these salts on my farm. Common salt is not a manure, and we may

as well so decide once for all.

After an experience of nearly a quarter of a century in conducting an experimental farm, I have reached the conclusion that the growth of our fruits and most of our cereal crops is best promoted by the use of a fertilizing mixture, made up of finelyground fresh bones and good wood ashes. This mixture I arranged and recommended twenty years ago, and I find, after persistent soil experiments extending over many years, that I am using it more freely than ever.

This

My method of preparing it is, to take six barrels of pure raw bone flour and twelve of good wood ashes, and mix them well together upon a shed floor, adding, during the mixing, twenty buckets of water and one barrel of gypsum or plaster. mixture may be allowed to stand a few weeks, or it may be used at once if needed. If permitted to stand long, it heats from chemical action, and the freed ammonia is in part fixed as a sulphate by the plaster, but not all of it.

For fruits of every kind I know of no better fertilizing material, and as it supplies every needed element of nutrition, its effects are remarkably persistent and immediate.

But, gentlemen, I must detain you no longer. I cannot think that I have presented anything new or of special value to a company so intelligent and experienced as this. There are old facts and forms of knowledge which it is well to call up for consideration occasionally, as we often find that the good and excellent have been neglected because they are old.

On inquiry, Dr. Nichols added, in further explanation of the chemical composition of sugar, that it is a compound of pure water with carbon—absolutely pure water with the elements of a diamond. It is a very unstable compound: when placed over the flame of a lamp the water escapes, and the carbon is brought to view. A molecule of sugar is like a watch-spring wound up: the struggle between the chemical forces is towards change into lower combinations. A potato is but a mass of starch, and can

be changed almost entirely into sugar. The change of starch into sugar requires the presence of diastase, which is a starch solvent apparently provided for a specific purpose. Sugar cane a few weeks before it is ripe has no sugar: after it is mature it has no starch,-and the case is the same with most fruits. The production of sugar is not exhaustive to the soil: the refuse from the manufacture of beet sugar returns to the soil all inorganic substances taken from it. In strawberries there are three kinds of sugar, two of which are uncrystallizable and one crystallizable. Most pears contain uncrystallizable sugar. The orange will grow in sand with the addition of potash and lime. The Black Hamburg grape, when ripe, has about seventeen per cent. of glucose, and its juices are most agreeable, though we cannot tell precisely why. Changes in fruits go on with great rapidity at the time of ripening. Beet sugar is as sweet as cane sugar. The chemical composition of milk sugar is the same as that of cane sugar, but it has only one third of its sweetening power. We have in the sugars interesting examples of isomerism,-bodies, so far as we can distinguish, constituted alike chemically, but having very unlike physical proper

ties.

Dr. Nichols also stated that wood ashes are often adulterated. He bought one lot from Canada which contained by analysis nine per cent. of potash, but the next lot had less than four per cent. He regarded the discovery of the Stassfurth potash salts as providential; the supply is enormous, millions of pounds being produced each year. In kainit there is so large a proportion of common salt that it is apt to kill grass. The chlorides of potash may be mixed with phosphates and nitrate of soda, and extended with humus, so as to form composts closely resembling stable manure in concentrated form. The Stassfurth salts are now brought to this country and used by official analysis made at the salt mines, and these determinations are usually safe and reliable.

FLOODS CHECKED BY RE-WOODING.

BY S. W. POWELL, IN SCIENCE MONTHLY.

Professor Guyot taught that variety of coast-outline, of elevation, of climate, and natural products, is necessary for the richest development of the individual and of society; and that in no part of the world were so many of these favoring conditions originally brought together as in the regions bordering the Mediterranean.

The Roman empire, which, at the time when it was most widely extended, consisted almost entirely of the countries lying around or near this sea, had the best situation of any of the great empires that have arisen. The grouping and arrangement of the land and water masses; the diversity of elevation and of coast-outline; the rich and varied scenery; the wide range of animal, vegetable, and mineral products; the great number of populous, wealthy, and nobly built cities, with the marvellous Roman roads binding them together, and the majestic Roman law coördinating their civic life,—all coöperated to make this region the garden of the world. The fact that the most favored part of the earth's surface should have been so nearly ruined, as it has been, by selfish and short-sighted treatment of the forest, its most precious possession, ought to have been a lesson to all future settlers of new territory. That it has not been heeded by the settlers of North America, the increasing frequency and severity of floods and droughts, and the swift and menacing approach of timber-famine, plainly prove.

The streams which flow through the valleys that wind back from the sea into the heart of the mountains and hills bordering

the Mediterranean, would, in their normal condition, be limpid and perennial. But, owing to this short-sighted cutting of timber from steep hill-sides, and to the equally short-sighted overpasturing of the cleared spaces afterward with sheep and goats, most of these streams were, in the upper part of their courses, changed into torrents, whose beds in dry weather are cheerless expanses of sand and gravel.

During heavy rain, or when snow is rapidly melted upon the mountains (and this is especially apt to occur when a warm wind, called the Fohn, coming probably from Sahara, and saturating itself with moisture as it crosses the Mediterranean, strikes the mountains-Guyot said he had known this wind to melt six feet of snow in twenty-four hours), these torrent channels are almost instantly filled with furious, short-lived floods, which often sweep off bridges, buildings, crops, and even animals and human beings, besides tearing up costly roads, and wash away a vast amount of precious soil from mountain-sides where it is sorely needed, and deposit it in rivers and harbors where it is a nuisance, and often a serious peril to navigation.

In their gullying and undermining rage, these torrents tear out stones and large rocks from the hill-sides, grind them up into gravel and even fine sand, and ruin much fertile land upon which they spread this material.

But there is further mischief, which, as being more widely diffused, is less sure to be assigned to the true cause-the stripping steep land of its covering of trees.

1. There is the failure of springs, because water of precipitation, which should have been delayed upon the hill-sides by the roots, sprouts, mosses, fallen leaves, etc., which fill and cover the surface of the ground under a forest, till it could find the underground spring-sources, runs off the bare slopes in a few hours. Dry springs mean parched pastures, small crops, and unprofitable husbandry.

2. The increased cost of buildings, bridges, furniture, and implements of all sorts, which are, in whole or in part, made of wood. A large item in the current expenses of railroads is the outlay for ties, which must be renewed frequently. Wood for fuel or structural uses is a prime necessity of civilized life; and, as it is bulky, its cost increases rapidly with the distance