The doctor at home and nurse's guidebook / edited by George Black.

Date:
1909
Catalogue details

Licence: In copyright

Credit: The doctor at home and nurse's guidebook / edited by George Black. Source: Wellcome Collection.

    125/684 (page 97)
    CHARCOAL FILTERS of other portions of the nervous system. CERVICAL VERTEBRJE The term applied to the upper vertebrae of the spine situated in tae neck, or between the base of the skull and the shoulders. It is interesting to note that the number of cervical vertebrae is the same in all the mammalia (that is, animals that produce their young alive). Thus the necks of man, the whale and the giraffe contain equally seven separate vertebrae. CESSPOOLS, EFFLUVIA FROM In seeking to counteract the effluvia from cesspools, drains and the like, either when their contents are being removed or when they are being cleansed, a liberal use of dis- infectants is necessary. Deodorizers are of no advantage whatever. They simply replace one odour with another, leaving the germ-laden air absolutely untouched. It is the thing that causes it and also the microbe-saturated environment which call for attention. CHARCOAL First in efficiency, cheapness and availability of artificial antiseptics, deodorizers, and disinfectants, is charcoal. The disinfective proper- ties of charcoal are due almost entirely to its great porosity. Lie- big states that the pores in a cubic inch of beech charcoal must, at the lowest computation, be equal to the surface of one hundred square feet, and some chemists have estimated it at more than double this amount. By reason of this peculiar physical structure, the charcoal becomes endowed with a remarkable capa- city for absorbing and condensing gases ; and hence, when it is ex- posed to an atmosphere containing • D.H. the putrid products of decomposi- tion, it quickly absorbs them. Thus far the action of charcoal is strictly mechanical, but'it does not stop here, for when once the miasma becomes stored in the pores of the coal, a secondary and chemical ac- tion is promoted by reason of the intimate contact of the former with the air condensed also in the char- coal. This contact causes rapid oxidation to take place, and as oxidation is a species of combustion, the putrid matters are burned up and destroyed as effectually as if - they were passed through the ignited coals of a furnace. Freshly burned and broken charcoal will absorb from ten to fourteen per cent, of its own weight of gases and moisture from the atmosphere during a period of twenty-four hours, and it is capable of absorbing ninety times its own volume of ammonia, or fifty-five times its own volume of sulphuretted hydrogen. The dis- infecting and deodorizing power of fine charcoal depends upon its being both fresh and dry. Charcoal loses its absorptive and disinfecting power in a great degree by use, but can be restored to full efficiency by moderately heating it. CHARCOAL AIR-FILTERS The use of charcoal air-filters, consisting of a layer of charcoal in coarse powder, varying in size, according to circumstances, between a small bean and a filbert, has been strongly recommended for ventilat- ing purposes. The charcoal is placed between two sheets of wire gauze, fixed in a frame, and can be readily applied to buildings, ships, to the air-shafts of sewers, to water-closets, and various other purposes. All the impurities of the air are absorbed bv the charcoal, so that a current of pure air alone H