HEALTH COLUMN.

Otago Witness, Issue 3084, 23 April 1913, Page 68

HEALTH COLUMN.

CLOTHING AND HEALTH

The study of clothing in relation to health has received cf late years closer attention than ever it did before. ihe principal use of clothing is to conserve the enimal heat of tho body; but with this duty it combines the subsidiary purposes of serving for decency, for the adornment of the person, and for protection against injury. Conservation of the body heat is especially necessary in temperate and Arctic climates. In warm and tropical regions, on the other hand, clothing fulfils the purpose of personal adornment and bodily protection chiefly. —Heat and Cold. — Tho human bodv is capable of resisting heat and cold through a very considerable range of temperature, but is more able to withstand extremes of beat than of cold. This might be predicted from the fact that the animal body is a great heat-producoi in relation to its size, food being the fuel, and the bodily organs the furnace in which tho fuel is burned by chemical action; but tho total amount of heat generated within a given period is, however, limited at the best. The object of clothing, therefore, is to prevent this body heat being dissipated too rapidly from the body. —Material cf Clothing. Tho materials of which the different fabrics are composed arc obtained almost equally from ttje animal end vegetable worlds. From the animal world arc obtained wool, silk, skins, hair, and feathers; from -the vegetable kingdom we obtain cotton, linen, jute, hemp, guttapercha, and straw. These different stuffsaro used cither pure or mixed, and compose, in the main, the different fabrics of which tho body coverings made. Tho different materials differ greatly in the rate at, which they allow air or water to pass through them. —Permeability to Air. — Thus different cloth stuffs, of exactly similar size, when subjected to the same test, exhibit differences in the respective amounts of air which may be passed through them in a given time. Suppose flannel, linen, silk, and leather to be taken for the test. Tho result will show that 100 parts of air will pass through the flannel for 60 of linen, 40 of tho silk, and about 50 of tho leather. The porosity of permeability of these substances wiil, therefore, be in the order named. —Absorption of Water. — If pieces of new silk, linen, cotton, and flannel of exactly similar size be taken and placed flat-ways anti lightly upon the surface of cold water, they do not float for equal periods of time. Silk sinks almost at once, linen in about one minute, cotton in about 4i hours, and flannel docs not sink at all. This experiment shows, approximately, the rate at which garments made of tiiesc respective stuffs will become saturated with damp. If worn materials be used in the experiment, and warm instead of cold water, absorption is relatively more rapid. —Heat Properties.— Tho heat-conducting capacity of different textile fabrics is by no moans the same. Cotton and linen, especially tho latter, feel colder to the touch than silken or woollen articles. They arc, therefore, better heat conductors than the latter—that is to say. in tho same time they rob the body of more heat. This . conductivity, however, does not depend so much upon the materials themselves as upon tho closeness or openness cf the woven, texture. Tho fluffier the material the more air is held within its interstices; and hence tho heat of the body is conducted away less rapidly. The roughness of the fibre of wool, as compared with those of linen, or cotton, or silk, by setting up some degree of irritation of the. skin, and, therefore, a greater supply of blood to that part than usual, doubtless contributes in some measure to the greater sense of warmth cf a woollen garment, and. for a like reason, is ill-borne by hypersensitive persons. —Perspiration.— This is a matter of considerable practical importance. Cotton, linen, and wool behave differently. Experience amply demonstrates that when garments worn next tho body, and composed of these materials respectively, become wet with- perspiration, a feeling of chilliness is more quickly perceived in tho case of cotton and linen than of wool. Heat, therefore, is more rapidly abstracted from the body in the oa.se of the two former than of tho last. Hence chills are more liable to happen when cotton or linen is so worn. It may safely bo reckoned that, in the same time, damp cotton or linen abstracts not. loss than 30 per cent, more heat from the body than d-o'-s damp wool. They also act differently in regard to the solid and limiid portions of perspiration. Cotton and linen retain more of the solids than flannel or wool, and, therefore, more quickly become apparentlv soTcd than wool, whereas woo! permits the solids to pass through, to soil the garment worn next above, while it itself remains clean apparently longer. —Colour of Material.— The colour of a garment has an important bearing on the amounts of radiant heat alvorbod and reflect'd. White and tho lighter-coloured fabrics absorb less radiant heat than dark coloured or Mack, and reflect more; and the difference in amounts are graded bv the toms of colour between white and black. —Clothing and Climate.— No one dross standard is equally suitable for all points of the globe In the cold or Arctic regions experience has shown that the cold ran be overcome by wearing woollen garments next the body, and over these the skins of anima's with the furrv side inwards No other forms cf clothing will adequately conserve the bodv heat. In the so-callr-d temperate climate more difficulty is experienced in regulating the proper clotlrng than in any other, solely duo to the unexpected fluctuations of temperature. In these islands there is also

the additional fact that the atmosphere is largely charged with watery vapour, and particularly on the west coast. There is no season of our average year in which woollen underclothing can be safely dispensed with. It may be thicker or thinner in make, close or open in texture, as the weather permits, but it should be constantly worn, consistent with the safety of the person. Attention to this point would considerably minimise illness and temper its severity.