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Page:Popular Science Monthly Volume 32.djvu/735

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the face of these facts, it is not to be wondered at that "sewage farming" has not proved a commercial success. We must, indeed, be in doubt whether, when the circumstances are more than usually unfavorable, it exercises any very great purifying action upon the putrescible mixture. In the treatment of putrescible refuse we have to aim at nitrification rather than putrefaction, and it is certain that by mixing with water putrefaction is encouraged and nitrification delayed. It seems to be almost incontestable that the proper course to pursue with regard to organic refuse—putrescible matter—is the very reverse of what we do pursue. We clearly ought to encourage oxidation and make putrefaction impossible. Putrefaction is certainly a great cause of ill-health. The putrefaction of organic refuse when mixed with water has, Dr. Poore thinks, been the chief cause of the development of modern sanitary progress—that is, of the need of doing something. Our forefathers were not given to this method of treating putrescible matter. House-slops trickled along open gutters, and excremental matters were deposited in dry pits.


Cameo-cutting for Amateurs.—Mrs. Henry Mackarness, in her "Young Lady's Book," represented cameo-cutting as an art simple enough to be acquired without great difficulty, which would "give young ladies a new and elegant pursuit." Only two kinds of tools are used, which are named the scawper and the spit-sticker. The work is performed at a bench or table, furnished with suitable gripping apparatus, the shell being fixed with setter's cement on a stick, which may be made of a five-inch section of a broom handle. Care should be taken to select a piece of shell without a flaw. Beginners should choose tolerably smooth pieces; but practiced workers prefer those which are irregular in their surface, because they furnish more scope for the exercise of skill. In cutting these the design follows the convolution of the shell. Care must be taken in cutting not to let the ground show through; but a skillful cutter will so arrange his design as to produce the blush of the ground in such portions as to enhance the value of his work. Shells are further liable to the faults of displaying crooked lines in the cutting, which are believed to have been the work of worms in the earlier stages of their development, and of "flaking." Beginners will draw the figure before attempting to cut; but a skillful operator will cut away at once, and rough out the head and face of a portrait very quickly. A workman can cut a portrait from a photograph in a few hours. The beginner should not spend more than two hours at a single sitting. In beginning, the learner should cut a few simple outlines, such as are furnished by the rose, the lily, or the fuchsia; the hand soon becomes accustomed to the use of the tools, and the timid cut becomes exchanged for the vigorous and graceful stroke of the artist. Great care is necessary in working the shell so as not to cut into the ground, on account of the extreme difficulty of removing any marks. Marks are removed by the use of powdered pumice-stone and water, applied on a piece of pointed wood; the next process is to smooth the surface with pumice-stone and oil; wash with a soft brush and warm water, then polish with the dust of the rotten-stone and sulphuric acid, mixed to a paste, and applied on the point of a piece of wood.


Vaccination and Erysipelas.—A report by Dr. Airy, on three cases of so-called fatal erysipelas after vaccination, will help in forming a judgment of the sort of foundation on which the fears of an outcome of this character rest. The three children were vaccinated by three different practitioners. In the first case the erysipelas set in too late for it to be possible for vaccination to have had anything to do with causing it; in the second case the child was surrounded with erysipelas in the surgery where it was brought to be vaccinated; in the third case no definite source of erysipelatic infection could be discovered, but the child lived in a low-lying place, close to swampy and unhealthy meadows. Thus, none of the cases were traceable to the vaccine lymph; and its innocence is attested by the fact that other children were vaccinated with the same lymph without the occurrence of untoward symptoms. The question arises next as to the degree of danger of erysipelas entering the vaccination-scratch, or the wound left by a ruptured