Reference is next made to a recipe for keeping old strawberry beds in bearing, from the Friend's Review. The application, attended with remarkable results, was as follows:

"Of nitre, of potash, of glauber's salt, and sal soda, each one pound; of nitrate of ammonia, one-quarter of a pound - dissolved in thirty gallons of water. One-third was applied at a time," to a bed 30 feet by 40. Three applications being made at intervals of a week. Frequent waterings of soft water, were also used in dry weather.

Various statements are next noticed, from Prof. Johnston's lectures, with regard to the efficacy of potash and soda.

Dr. Hull concludes from these data, that "the results confirm in the main, the general rule for specific uniform nutrition. Potash, the major element of the analysis, holds the highest representation in the production of plant and fruit; ashes, (potash and lime - the latter, also, an important substance in the analysis) present the next claim, and phosphate of lime (holding a questionable or minor place in the analysis) produces the least satisfactory impression. Tet the careful obserrer will perceive, that the potash alone, is quite equal to all the requirements of the plant in the department of inorganic constituents, and even here enforces its place as one of the special constituents, which is demanded as an increased, correspondent and specific nutrition, that bears no proportion to that of the exact analysis".

Let us see. The potash of the analysis of the strawberry is, or ought to be, chemically pure; that of Dr. Hull's experiment, was commercial potash, containing all the soluble constituents of wood ashes, sulphates, carbonates, phosphates, and silicates of potash and soda, together with salt of lime and magnesia, and chlorine. This potash, itself containing nearly every inorganic ingredient of the strawberry, is neutralized with muck, which presents the same inorganic composition as wood ashes, and in addition, a large per centage of organic matter.

Dr. Dana says that the addition of potash to muck, furnishes a material equal in all respects to cow-dung, so that the plants which flourished so admirably under " potash nutrition " were supplied in addition to the substances contained in the soil, and no doabt abundantly, with a manure, including all the inorganic, and all the organic substances requisite for the most perfect production! It is easy to see that Dr. Hull's potash is synonymous with good stable manure, and "alone, is quite equal to all the requirements of the plant in the department of inorganic constituents," etc.

It is not surprising that ashes, treated with muck, should be less valuable than potash^ if used in equal proportion, because they contain less soluble matter; and mere bone-dust cannot be supposed to exert the beneficial action that is exhibited by a manure abounding in more soluble phosphates, and all other required ingredients.

In the case of the application of nitre, potash, glauber salt, sal-soda, and nitrate of ammonia, we have potash, soda, and ammonia; sulphuric, nitric, phosphoric, silicic, and carbonic acids. Quite a variety of nutriment, the main efficacy of which is probably due to ammonia and nitric acid; at any rate there is no reason to ascribe it exclusively to potash and soda, as seems to be done by Dr. Hull.

The exceptional cases are in some sense interesting. It is useless to speculate upon the causes of the apparent anomalies, without a basis of repeated and comprehensive experiments, made with a full knowledge of the conditions that may affect their accuracy.

Reserving to the close of the article, some further observations suggested by this part of the subject, I shall notice briefly Dr. Hull's remarks on the organic nutrition of the strawberry. He quotes an analysis, representing the organic constituents of the strawberry to be "citric and malic acids, and a large proportion of mucus sugar." This mucus sugar is undoubtedly a mixture of grape sugar, and some combination of pectic acid. Dextrine and woody fibre must be added to the list on analogical grounds. The analysis is obviously incomplete.

Dr. Hull, on the authority of Prof. Mapks, adds tannic acid to the list of ingredients. Prof. Mapes asserts, that it exists " in the cortical or external surface of the fruit, that he has detected it by subjecting a large quantity of these surfaces to the appropriate chemical tests. He attributes the flavor and fragrance of the strawberry to the specific property of this acid, and has found tan-liquid, a most valuable watering for the plant".

Dr. Hull adduces various instances of the beneficial effects of tan-bark as mulchlirg, and of tan-liquid as a watering. He assumes, with Prof. Mapes, that tannic acid is a specific nutrition for the strawberry.

Every chemist knows that a solution of one part of per-chloride of iron in 200,000 parts of water, gives a characteristic blueish-black tint with tannic acid, and that the 800,000th may be detected. I know no reason why the converse of this statement is not true why one two-hundred thousandth part of tannic acid may not be detected by the salt of iron. If with this exceedingly delicate means of discovering tannic acid, Prof. Mapes, could only find it by using a large quantity of the cortical surface of the strawberry, it may be questioned whether the tannic acid has a very large influence on the flavor of that fruit!

Tannic acid is however readily detected in the leaves and stems of the strawberry, as I have this day observed, by the use of the above mentioned test. Still the quantity is small, as nothing of the intensely bitter taste of tannic acid can be perceived. In order to test this predicate, (Prof. Mapss' presentation of tannic acid as a constituent of the strawberry,) and the comparative powers of the citric and malic acids, as "nutrition for the strawberry,"

Dr. Hull made a series of experiments, on "three rows of each variety, of four different kinds of strawberries, which traverse his triple bed of inorganic manures. The liquids were applied from May 18th to June 23d, twenty-five times. The liquids were: -

Tannic acid - in the fom of tan-brark liquor, one gallon to one hundred of water; Citric acid - juice of one lemon to four gallons of water; Malic acid - one pint of cider to four gallons of water; Manure water - manure liquid of the barn-yard; Poudrette water".

• I must refer the reader to the August Horticulturist, for the details of these experiments. The general result was that the tan-liquor produced the best yield always, as regards quantity, and generally with respect to quality.

This result has its practical value, which cannot be denied; but has it received the correct explanation? Without assuming to give the correct explanation on so insufficient data, I beg to indicate some reasons, that in my mind show that it is yet unproved, that tannic acid has produced these effects. I do not deny that it may be the principal agent; but I conceive that Prof. Mapes' assertion, though having a degree of plausibility, remains to be demonstrated.

What is Dr. Hull's tannic acid? Is it the very nearly pure substance? It is tan-liquor - whether fresh or spent, furnished by oak, hemlock, sumach or catechu, he does not tell us!

May there not be many other substances present in it besides tannic acid? We know that the bark of trees is rich in inorganic bodies. Can they be excluded from participating in the effect? The ready passage of tannic acid into gallic acid is well known. Is it not worthy of consideration? It has recently been discovered in the Giessen laboratory, that tannic acid is a compound of gallic acid and sugar, and since it readily decomposes* into these two bodies, they may with as much propriety be concerned in the nutrition of the plant. However, we know nothing about it.

In two cases, the strawberries in Dr. Hull's experiments, that he fed with malic acid, were adjudged to possess the highest flavor. What is Dr. Hull's malic acid? Cider! containing, according to Dr. Salisbury's analysis, alcohol, sugar, dextrine, malic acid, phosphates and sulphates of the alkalies, with a little tannic and gallic acids.

Says Dr. Hull - "Here arises an important inquiry - how much of the flavor allowed to the malic acid, must be attributed to the tannic acid which the cider contained?" It may not, perhaps, be irrelevant to inquire what part of the flavor of cider, or of cider apples, may be due to tannic acid?

What effect may the alcohol, sugar, and alkaline, phosphates, and sulphates have had on the strawberry flavor?

Dr. Hull does not specify the age of his cider, a matter of much importance; for it is well known that malic acids and its salts easily enter into decomposition.

Tannic acid is adduced by Dr. Hull, as one of those substances that "is demanded as an increased, correspondent and specific nutrition, that bears no proportion to the exact analysis," because the strawberry contains but a trace of it, while it seems to be so largely appropriated by the plant.

But where is evidence that tannic acid has any thing to do with the nutrition of the strawberry? Have not other cultivators produced strawberries equaling those of Dr. Hull, without application of tannic acid?

I conclude, therefore, that Dr, Hull's experiments furnish no satisfactory evidence of the truth of his closing statement, that the practical cultivator can perfect the finest fruit in abundance and richness, by selecting potash from among the inorganic, and tannic acid from among the organic constituents of this delicious gift from the " Giver of all good." At the same time, abundant testimony is furnished of the efficacy of tan-bark as a mulching, and of " potash neutralized with muck," as a fertilizer.

However valuable Dr. Hull's experiments may be, practically, they are entirety too ▼ague to have any effect in establishing theory.

His fertilizing applications are either of very complicated, or of almost unknown composition. Necessarily the quantities of each are felso unknown. The soil is unanalyscd. Organic and inorganic manures are used on the same plants. The physical and physiological conditions of the plant are not taken into the account. In fine, the sources of error are so numerous, and so little understood, as to be incapable of elimination.

Thus much of criticism, I have thought due to rational culture, and conclude by expressing a hope that I have not misunderstood nor misrepresented Dr. Hull's statements.

Samuel W. Johnson.

Deep River , Lewis co., N. Y., November, 1852.