In his recent work on Nitrogenous Manures, Prof. Paul Wagner, director of the experiment station, Darmstadt, mentions a fact of great value in this connection. He says: "In my experiments a rape plant, freely manured with nitrate of soda, took up so much nitrogen that in its young state it contained no less than 6 per cent. of that element. Some weeks later the size of the plant was doubled, and the amount of the nitrogen in it was only 3 per cent., and still a few weeks later it was quadrupled in size and the quantity of nitrogen in it had sunk to 1½ per cent." "It is wrong," he continues, *' to suppose that nitrate of soda acts on the plants while it is in the soil; the nitrate is very soon no longer in the soil but in the plant, and in this position it produces a striking increase in the size of the plant. As the plant-substance increases, the percentage of nitrogen contained in it diminishes continuously until it has reached the minimum, and then the action of the nitrogen, and with it the increase of produce, ceases".

This is an important fact. Plants get their carbon (sugar, gum, starch, woody fibre, etc.) from the carbonic acid of the atmosphere, but the nitrogen and the ash ingredients come from the soil. Not less than fourfifths of the dry substance of plants comes from the atmosphere. When Mr. Barry tried to get a rapid, vigorous growth of pear leaves early in the season, in order to ward off an attack of leaf-blight, his real object was to get the leaves full of sap, and a sap overcharged with nitrates, phosphoric acid, potash, etc., so that they could take carbonic acid rapidly from the atmosphere and make a vigorous, healthy growth.

It is the chlorophyll or the dark green coloring matter of the leaves, under the action of the sun, that enables them to get the carbonic acid from the atmosphere. In this country, as a rule, we have plenty of sun, but, especially early in the spring, our plants are deficient in chlorophyll. And this lack of chlorophyll is owing to a lack of nitrates. These are well known facts.

As we have before said, Mr. Barry must have found it difficult, if not impossible, to get a sufficient quantity of nitrates early in the spring without furnishing more manure than the trees required the latter part of summer or early autumn, when nitrification of organic matter in the soil, under the action of heat and moisture, often proceeds with great rapidity. But by the use of chemical fertilizers containing nitrates we can now obtain a rapid growth in the spring without producing a too luxuriant growth in the fall.

It remains to be proved that the rapid vigorous growth before midsummer has a tendency to resist the attacks of blight, yellows and other diseases. Some of our authorities say it will not do so. But so far as we have seen they have made no satisfactory experiments on this point. Our own practical trials (not experiments) with nitrate of soda and other fertilizers seem to indicate that a rapid, vigorous growth of trees often enables them to resist fungus diseases. But there are exceptions. Last year the leaves on our apple trees, after the severe frost in June, were seriously attacked by fungus and rose bugs, and several acres of currant bushes, those which had had a dressing of nitrate and those which had not, were all attacked with leaf blight, and our peach trees, with and without nitrate, were all destitute of fruit. In previous years nitrate of soda had proved wonderfully efficacious in increasing the healthy growth of leaves on peaches, apples and currants, as well as the size, quality and quantity of the fruit. And even last year it had a decided effect on raspberries, strawberries and other plants that escaped the frost.

On the whole, therefore, theory and practice alike warrant us in hoping that a rapid, healthy, vigorous growth early in the season will enable our plants, at least to a considerable extent, to ward off fungus diseases as well as attacks of insects. And this can be best obtained by the liberal use, in conjunction with phosphoric acid and potash, of fertilizers furnishing nitrates. The fact is, that more attention has been paid to the introduction of improved varieties of fruits, flowers and vegetables than to the science of feeding them. The pomologists and gardeners have got ahead of the chemists and fertilizer manufacturers. With plants as with animals, good feeding must go hand in hand with good breeding. Joseph Harris.