This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
The pears exhibited by Dr. Boynton, of Syracuse, at the last meeting of the American Pomological Society, attracted much attention from the unusually waxy and glossy appearance of the skin, and the extraordinary brilliancy of their coloring. Dr. Boynton offered to the Society, in some extended remarks, his idea of the probable cause of this color and gloss of skin, but no correct report has yet been given of these remarks in any of our journals. The chief idea was, that the effect above noticed was produced by growing the fruit upon a soil containing a great variety of mineral or inorganic sub-stances, and by the free use of superphosphate of lime, and of potash, soda, and the common carbonate of lime, which, acting upon silica, produced the silicate of potash, the silicate of soda and lime in abundance, and thus created a covering upon the pears similar to the silicious coating on the corn-stalk. On this dense surface the rays of the sun pencil the prismatic hues with a degree of brilliancy and perfection rarely witnessed.
The doctor thought it not impossible that he could so perfect this metallic coating that he could, at some future meeting, present his best specimens of fruit with his own photographic portrait on their sides! *
I notice this matter now for the purpose of saying, that those who may wish to experiment in this direction may find some more convenient sources of obtaining the necessary materials, than were mentioned by Dr. B., as his supplies of alkalies were mostly found at the Syracuse Salt Works.
The use of the common "salt and lime mixture" (viz., three bushels of lime slacked with a barrel of brine, or one bushel of salt in solution) will give the chloride of lime and the carbonate of soda, which Dr. B. spoke of so highly; while common sour peat or muck, or even decaying straw, or old litter, or leaves, mixed with sand, will create, by the action of carbonic acid on silex, a large amount of soluble silica; and silica, or rotten, sandy rock, dissolved by carbonic acid, will in its turn, by liberating potash from the rock, now dissolve other rock, and form silicate of potash. Hence, sour muck and sand, with a slight addition of salt, lime, and wood ashes, will furnish a cheap and convenient means of producing the silicates which Dr. Boynton thinks such important agents in creating the dense, glossy, high-colored skin of his pears.
The usual method of top-dressing dwarf pear gardens with well-rotted carbonaceous composts in a degree produces the same effect as the above mixtures, and the result, we all know, is very satisfactory.
There is a good deal of plausibility in Dr. Boynton's theory; but we must not expect similar results from using the same means on all soils, for Dr. Boynton acknowledged that his soil was originally a sort of "conglomerate rock soup," made up of the contents of Lake Ontario basin, which no man can hope to imitate, or find elsewhere, in precisely similar combinations. It may be well, also, to caution amateurs, or unscientific persons, against the too free application of alkalies to fruit trees, as there have been cases lately, within my knowledge, where very intelligent persons have destroyed many valuable surface roots, and even entire trees, by too careless or too bold experiments of this kind. The "aesthetic former," says the oracular Ralph, "thinks a cow is a creature fed on hay, and gives a bucket of milk twice a day. But the cow that he buys gives milk for three months, and then her bag dries up." Pear trees are very much like milch cows; they require to be fed and managed by a practical hand, or they too will "dry up" most mysteriously sometimes.
I by no means reject the aid of science; I only wish to warn Mr. Jesse Rural against excessive fondness for chemical experiments in his first efforts in the garden.
[This caution is a necessary one, for the young experimentalist generally "goes it blind." We are somewhat inclined to doubt whether the beautiful "face" on Dr. Boynton's fruit was produced by additions of his own; it is quite likely, if we may judge from his description, that the salts were naturally contained in the soil. We must accord him the merit, however, of having noted the fact, and led the way in making experiments to produce the same results by the addition of salts and alkalies, in proper proportions and combinalions, in soils not naturally containing them. Certain localities (around Boston, for instance) have long been noted for producing pears highly colored and very glossy; others, again, (as portions of New Jersey,) are noted for producing the same kinds of pears of a deep russet. This, unquestionably, is owing somewhat to the mineral constituents of the soil, but probably quite as much to careful culture. The subject is one of peculiar interest, and we hope Dr. Boynton and others will follow up the experiment, and make a note of the result. - Ed].