Page:Popular Science Monthly Volume 10.djvu/136

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126
THE POPULAR SCIENCE MONTHLY.

odor, in all respects as inviting as at first. It is partially cooked, and needs but little treatment more to prepare it for the table. A German government commission has made experiments with this process, and two naval vessels dispatched on a voyage of circumnavigation were provisioned with this kind of meat. An establishment has been set up in Hungary for preserving meats in this way.

 

Causes of Putrefaction and Fermentation.—A year or two ago, Dr. J. Dougall, of Glasgow, at the Social Science Congress, held in that city, announced, as the result of investigations made by himself, that the presence of an alkali determines putrefaction in organic matter, while the presence of an acid determines fermentative changes. The same line of inquiry has been taken up since by Dr. John Day, of Victoria, Australia, who finds in Dougall's discovery an explanation of the presence in hospitals of septic poisons, giving rise to pyæmia, erysipelas, and puerperal fever. The Sanitary Journal, of Toronto, has a paper by Dr. Day upon this subject, the purport of which may be briefly stated as follows:

Hospitals, as usually constructed, have alkaline ceilings, alkaline walls, alkaline floors (owing to the use of soap in cleansing them). Experience has shown that pyæmia is of extremely infrequent occurrence in temporary hospitals consisting of rough wooden sheds. The incessant generation of peroxide of hydrogen by the turpentine of the wood doubtless prevents putrefactive changes, but, as turpentine always gives an acid reaction, this circumstance must greatly increase the disinfecting power of the peroxide, by determining the fermentative instead of the putrefactive decomposition of the pus-cells and other organic matter given off from the patient.

Dr. Day proposes the following method of counteracting the evils of hospital-life: The boards of the floor he would first cover with a coat consisting of equal parts of gasoline and boiled linseed-oil, to which is added a little benzoic acid. When dry, the surface is polished with a paste of beeswax, turpentine, and benzoic acid. Boards so prepared are, in his opinion, rendered permanently disinfectant. The walls and ceilings might be rubbed smooth, and coated with a varnish of paraffine or oil of turpentine; or, better still, they might be coated with silicate paint, then rubbed down and varnished. For the purpose of keeping the air pure, and destroying the pus-cells floating in it, he recommends, in addition to ventilation, the use of certain volatile substances, such as gasoline, benzine, and eucalyptus oil. The furniture should be occasionally brushed over with either gasoline or benzine, in which a little benzoic acid has been dissolved.

 

Cultivation of Caoutchouc-yielding Trees.—In 1870 Mr. Clements R. Markham advocated the planting of caoutchouc-yielding trees in India, and in 1873 the first attempts were made, but without success, in the Darjiling Terai and in the district of Goalpara, Assam. In the following year two plantations were made in the Kamrup district of Assam and at Charduar, at the foot of the Himalayas, in the Durrung district. The latter plantation now covers 180 acres, and in 1875 there were in it 16,401 live cuttings. The species here cultivated is the native Ficus elastica. Several plants of the castilloa tree of South America are now in a very flourishing condition at Kew Gardens, and a good supply of this species has been thence forwarded to India, where they will form the nucleus of extensive plantations. In June of the present year an agent was to have been sent out to Brazil to collect healthy young plants of the hevea, the tree which yields the famous Pará India-rubber. Thus provision will be effectually made against the extinction of these valuable species of plants.

 

Inspecting Railways by Machinery.—Attached to the rear of the paymaster's car on the Pennsylvania Railroad, says the American Manufacturer, is an apparatus which it is thought will work much more satisfactorily than the telegraphic instruments formerly used by the officers while making their tours of inspection. A roll of white paper, 700 feet in length, encircles a cylinder, from which it is paid out at the rate of three feet to the mile run by the car, its forward movement being regulated