Mr. Joseph Harris's article on "Fertilizers for the Garden" in the May number of this journal is no doubt as sound as a dollar in the general principles which it advocates ; but the instances which he cites in proof of his conclusions are possibly open to criticism.

For a year or so past certain writers have advocated a more generous use of nitrate of soda, in a way to lead those who have given little thought to chemical fertilizer questions to assume that it is in itself a fertilizer which will insure a profitable increase of crop regardless of the needs of the soil. The Mural New- Yorker has therefore repeatedly cautioned its readers not to use nitrate of soda (or nitrogen in any soluble form) unless it is known that the land is already proportionately supplied with available phosphoric acid and potash. Nitrogen is neither more nor less valuble to the gardener or farmer than is either of the others. It is by far more costly, and, while the phosphates and potash remain in the soil for subsequent crops, nitrate of soda leaves us even before the current crop is harvested. We do not need to tell our distinguished critic this. He knows it, and has taught it in his writings for many years. And yet we place Mr. Harris among those who, while cracking up nitrate of soda, has not, in every case or in most cases, emphasized sufficiently the insuperable importance of a corresponding supply of minerals.

Mr. Harris assumes that the chemical fertilizers of to-day contain too small a quantity of nitrogen; that the minerals (potash and phosphate) are the strong links, and that a deficiency of nitrogen is the weak link of the chain by which the crop, in due proportion, will be diminished. This is true without a doubt in a majority of cases, and it is well that it is true, for if the farmer is to lose a part of the money he pays for fertilizers, he would better invest it in food constituents of a lower cost which will remain in his soil, than in nitrogen at a higher cost, which takes its leave after a single season of service. If a farmer from experimentation is fairly confident that his land is especially short in nitrogen, let him buy fertilizers with a high ratio of nitrogen; but if he knows nothing about it, the very best thing he can do is to buy high-grade complete fertilizers and use them until by experiment he finds that more nitrogen will profitably augment his crops. Then he may wisely add nitrate of soda, salts of ammonia or organic nitrogen as be, by trial in an inexpensive way on small plots here and there, may find them serviceable.

The advocacy of the use of one-sided, low-priced fertilizers on the part of the mixers ("manufacturers") and their agents, has done incalculable harm in the way of inducing those who till the soil to purchase fertilizers which do not furnish the full or partial meal which their land demands. The consequence is that they denounce fertilizers in tola. Thus, bone or South Carolina rock, kainit, superphosphates, ammoniated superphosphates, sold under high-sounding, taking names and at prices far below those of high-grade brands, are tried and condemned, not for what they really are, but as "fertilizers" which are assumed to furnish everything in the way of plant food that the name represents. So it is that in every case gifted and well-known writers, like Mr. Harris, whose words of advice are taken without question, should place all possible emphasis upon the economy of purchasing either high-grade complete fertilizers, or of "incomplete" fertilizers only as the farmer or gardener has learned from experiment that his land responds fully to bone, to potash or to nitrogen, and that the other constituents are not at present needed.

Mr. Harris says that it is a matter of surprise that the editor of the Rural New-Yorker does not see that his own experiments demonstrate that, so far as the production of potatoes is concerned, his worn-out soil was more deficient in nitrogen than in any other constituent of plant-food. "Superphosphate and potash, without nitrogen, did no good. They could produce no effect without nitrogen. Nitrogen alone on one plot produced 183 bushels per acre," or, we may add, 105 bushels above the average of the plots of natural soil without fertilizer. It is true that if this single trial be taken as a basis for comparison, Mr. Harris's reasoning is logical enough. It should be stated in fairness, however, that this little nitrogen-plot yielded more for some reason than any other nitrogen-plot either of that year's experiments or of those of preceding years. Another plot which received not only the same quantity of nitrate of soda per acre (200 pounds), but also 200 pounds of sulphate of potash, produced but 90 bushels of potatoes to the acre, or 12 bushels above the natural-soil plots. Again, raw bone (1,000 pounds), furnishing perhaps three or four per cent. of ammonia, gave but 77 bushels per acre.

Again, in our similar experiments of the year before, nitrate of soda (200 pounds) gave a yield but little more than the average of the natural-soil plots. The several no-fertilizer plots yielded an average of 143 bushels to the acre. Nitrate of soda (200 pounds) yielded but 125 bushels; sulphate of ammonia (120 pounds) yielded the same, nitrate of soda (200 pounds) and dissolved bone-black (400 pounds) yielded 168 bushels. Nitrate of soda (200 pounds) and sulphate of potash (300 pounds) gave 233 bushels per acre. Nitrate of soda (200 pounds), dissolved bone-black (400 pounds), sulphate of potash (300 pounds) - a complete fertilizer - gave 217 bushels. The Mapes Potato Manure (800 pounds) gave 257 bushels to the acre, while in the later experiments quoted by Mr. Harris 1,200 pounds of the Mapes (3.70 nitrogen guaranteed) gave a yield of 273 bushels to the acre.

From a glance at the experiments carried on at the experiment grounds of the Rural New- Yorker during the season to which Mr. Harris alludes, it is admitted that nitrogen alone gave a greater increase over the unma-nured plots than either potash or phosphoric acid or both. It is just as evident, withal, that in no instance was a large crop raised except when a high-grade complete fertilizer was used. Whether a smaller quantity of the fertilizer and an additional dose of nitrogen would have given as large a crop we have no proof one way or the other. If we were striving to raise the largest possible yield per acre, we would not use nitrogen in the form of nitrate of soda alone, but in the blended forms of nitrate of soda, sulphate of ammonia, dried blood, urate of ammonia and other organic salts of ammonia found in Peruvian guano, all of them soluble, but in varying degrees. Moreover, we should supply them, especially on light and fallow land, in minimum quantities consistent with experience, on account of their expense and the liability of loss by leaching. It is easy to supplement nitrogen to a growing crop by top-dressing, if it is thought that it will prove serviceable, as, especially in the form of nitrate, it is exceedingly prompt in its action.