Blue Glass.

Manufacturer and builder Volume 3, 1877

GEN. PLEASONTON'S REPLY TO CRITICISMS.

The open letter published by Gen. Pleasonton in Answer to various criticisms on his theories, commences with a vehement rejection of time insinuation of deception on his part, and a defence of his integrity ; but this is easily- disposed of by agreeing that he is honestly deceiving himself in his ignorance of the true nature of light in general and of the functions of the various colors contained in natural sunlight. If he were in the least acquainted with the results of the labors of the many eminent scientists who have devoted their lives to the careful practical investigations of this subject, with the aid of the most extensive appliances, performing the most laborious experiments, and in this way settling the nature of the effects of various colored lights beyond dispute, lie would not have rushed into rash conclusions, taken out patents for timings in which there is absolutely nothing, nor deluded himself and others in ascribing the success of some grape-growing, and the raising of a few pigs, calves, etc., to a few panes of blue glass, and ignoring; the true causes which are in the protecting influence of a glass roof, which does quite as well without the blue glass panes.

The General attempts to make a strong point of the fact that the Commissioner of Patents granted him a patent after having received the report of a so-called expert sent to use the grapes growing under blue glass, and perhaps also the calves and pigs revived and grown fat by the same means. The Commissioner of Patents in Canada, who also granted a patent after in-dorsing his explanation, is called "the highest scientific authority."

Now, this is something of a new argument; first, Commissioners of Patents are not scientific authorities at all ; they do not read one-tenth of the patents; they sign them on the recommendation of time examiners. These are the real authorities in their departments. Secondly, the Patent Office is not responsible for errors in a pretended invention, and therefore a patent is by no means a guarantee that an invention accom-plishes all that the inventor claims for it, hence time reason why there are so many worthless patents; but this is unavoidable, as the inventor ought always to have the benefit of any doubts, if they exist.

The attempts of Gen. Pleasonton to point out contradictions among scientists in regard to the effects of colored light on plants, simply show his failure to understand that when red and yellow light alone act on plants, and violet light does not, time latter will practically be equivalent to darkness; and as seeds require darkness for their development, violet light will not hinder it, while the developed plant needs all the undiluted sunlight, and a few panes of blue glass (one in eight, as in the prescription of Gen. Pleasanton) also will not hinder it, nor would a few panes of yellow, green, or red glass ; but certainly an illumination of exclusively blue glass might be as hurtful to vegetable life as any other color exclusively used.

The scientific statements of the General, which we published in our previous issue, (see page 51,) show sufficiently that his mind is in a muddle in regard to the truths taught by sound natural philosophy ; and in this respect he stands before the scientific world as a tyro would stand before professional ship-builders exhibiting to them a little boat carved with a jack-knife, and pretending to teach them something new - telling them that their whole theory of ship-building was wrong, that be is going to reform it, build on other principles, etc. The ship-builders would look upon this tyro as the scientists cannot help looking upon Gen. Pleasonton.

In regard to the indorsement of blue glass by a portion of the public, we must remember that what is called the public, believe in anything, such as mind-reading, clairvoyance, spiritualism and animal magnetism, believe in astrologers and and sea-serpents, etc., and even any sort of theological notions find adherents among sects of the most opposite opinions. Therefore the indorsement by the public of any novel vagary of this or any other sort, goes for nothing in the final de-cision in regard to its correctness. The excitement will blow over, and Gen. Pleasonton and his blue glass will have had their day, and then the public will laugh at the foolishness of the present hour.