The agricultural and horticultural publications of the present day, are teeming with the applications of science to the processes of husbandry and gardening. This is a fact of happy significance, and indicates how deeply the true means of advancement have taken hold, in the intelligent mind of the community.

Ordinary experience is the most usual, and an invaluable means of attaining excellence in the art of vegetable production.

Extraordinary experience or experiment, is a necessary adjunct to the former.

It is easy to make experiments and to multiply observations. It is just as easy to speculate upon them: but to make complete and exhaustive observations, and to plan and conduct strictly pertinent experiments, is quite another thing; as is likewise the arrival at Truth, which, to even the most patient and profound, often is liable to be confounded with speciousness.

Dr. Hull has made experiments, and written a lengthy article on the " nutrition of strawberries." I propose to inquire dispassionately - what are the merits of his investigations?

The article opens with a quotation from Prof. Emmons' " Agriculture of New-York," as follows: " The soil must possess all the inorganic substances, as well as organic, which are essential to the perfection of vegetables; if any one is wanting it must be supplied.*'

It will be necessary to remark somewhat upon this statement of Prof. Emmons. It is in a sense true, and is true as Prof. Emmons intended it to be understood, yet standing alone, it is capable of gross misconstruction.

The soil must contain all the inorganic substances that are essential to the growth of the plant, or the plant will refuse to mature. It must also contain all the organic elements of the plant in order to a profitable growth, but to grow the lemon, it must not necessarily contain citric acid, because citric acid is essential to the perfection of the lemon; nor need it contain morphine to produce the poppy, although morphine is essential to the perfection of the poppy plant.

In addition to all the inorganic substances of the plant, the soil must contain a quantity of decayed vegetable matter, in order to make it profitably fertile.

Such I deem a true expression of the sense of Prof. Emmons' proposition.

Dr. Hull remarks substantially, that although this rule is apparently true, and conforms to common sense; yet in its ultimates it admits of exception.

He states the ground of exception as occurring with reference to tannic acid, and alludes to other data bearing on the point, which disclose "evidence of the caprice of plants in imbibing nutrition at proportional variance with their analysis".

He says, further: "These discrepancies from the general rule, and the desire to awaken inquiry and experiment to the highest degree, in order to mature the finest fruit, have rendered me a little presumptuous, perhaps, in suggesting another rule of specific nutrition:

"That some fruits - whatever the organic or inorganic analysis of the plant or of the fruit may disclose and seem to require - possess one or more special constituents, each one of which is demanded as an increased, correspondent, and specific nutrition that bears no proportion to that of the exact analysis".

As I understand the above, it implies that certain plants flourish best when supplied with one or more ingredients in quantity greater than indicated by their composition. This is undoubtedly true in some instances. From the experiments of Prof. Way, it appears probable that ammonia is a means of supplying silica to plants, and therefore may be required in much larger quantity for the growth of highly silicious plants than would be indicated by the nitrogen found in the mature plant. But our present object is to examine Dr. Hull's proofs for bis presumed rule. His first statements refer to the inorganic ingredients of the strawberry. Three analyses are quoted, one of the fruit, and two of the plant.

His brief observation, on these analyses, which I need not quote, is sufficiently true - that in " the two analyses of the plant, the analysts coincide in the proportion of the potash: the discrepancy as to the other constituents is striking. In the analysis of the fruit by Richardson, the predominance of soda will excite some surprise, although the potash holds a second and very important position. At the same time the united analyses of plant and fruit exhibit as the proportion of potash, 59.72, and that of soda only 36.28." I may add that the analyses show in round numbers from 9 to 20 per cent, of phosphoric acid, and 12.26 per cent, of lime.

" Affirmative of the general rule," an experiment is adduced as follows: Last year, "a large bed was prepared and dirided into three equal portions; one containing potash neutralized by muck; another ashes, treated in the same manner; and last phosphate of lime, (bone dust.) Lines of the same plants, extended across the three soils. Boston Pine," and 14 other varieties, " displayed a sturdy growth throughout this entire triple tract; at the same time they exhibited a positive preference for the potash over the ashes; for the ashes over the bone-dust. The section of the triple tract, charged with potash, manifests an advantage this season much more conspicuous, the plants and fruit having gained at least one-fourth over their associates".

In the preceding experiment, certain varieties furnish different results, which Dr. Hull considers " exceptions to the general rule." "Black Prince and Burr's New Pine became almost worthless in the same potash tract; while runners of 1850, transferred from these same plants to the natural soil of my ground, well enriched with ordinary stable manure and street sweepings, have this year produced specimens of fruit nearly, if not quite equal to their best reputation. Buist's Prize also failed under potash nutrition, and devloped the richest foliage and finest fruit in the department of phosphate of lime (bone dust.) Hovey's Seedling failed in a tract of phosphate of lime, yet rejoiced with its luxuriant foliage and fruit in a tract of soil, supplied with lime as its main element".