CHAMBERS'S INFORMATION FOR THE PEOPLE. 



without proving to be too heating, or irritating, or 

 relaxing. In summer-time, if the flannel which 

 proved to be well borne in the colder seasons of 

 the year should be so far irritating and heating as 

 to relax or fever the system, this may be remedied 

 by substituting for it a thinner and finer quality 

 of flannel ; or, in extreme cases of this kind, an 

 under-garment of calico, of a proper degree of 

 thickness, may be substituted for the flannel at 

 that season of the year.' The use of chamois 

 leather as the under-garment is objectionable. 



But, strongly as the importance of having a bad 

 conductor of heat next the skin should be im- 

 pressed on the mind, there is a point connected 

 with it which is almost as important Flannel 

 ought not to be worn during night next the 

 skin. In bed, it is worse than unnecessary, for it 

 does harm : it then stimulates the skin, and pro- 

 duces a preternatural waste of the secretions, and 

 corresponding debility of system a corresponding 

 liability to suffer from the depressing influence 

 of cold a corresponding incapability of resisting 

 its influence. Dr Kilgour, in his Lectures on 

 Therapeutics and Hygiene, says 'that the use 

 of flannel was found to be beneficial in the 

 prevention of cholera, by maintaining the equi- 

 librium of the temperature and the functions of 

 the skin, and thereby preventing that derangement 

 of the bowels which is so general a consequence 

 of cold applied to the surface.' 



Cotton, though greatly inferior, ranks next to 

 wool in non-conducting properties. From its 

 comparative cheapness, lightness, and the facility 

 with which it can be cleaned, it has of late years 

 been gradually superseding the use of flannel as 

 an underclothing. But, though recommending 

 itself for these reasons, it can by no means be 

 considered as a perfect substitute for flannel, 

 either in temperate or in tropical climates, 

 whether used in a pure state or when mixed with 

 a certain proportion of wooL 



Linen, though inferior both to cotton and wool 

 as a non-conductor of heat, and as becoming more 

 readily wet, is now extensively used as an article 

 of inner clothing. It has drawbacks for this 

 purpose, however, arising from its being a good 

 conductor of heat. It rapidly robs the skin 

 of its free caloric ; hence the cold feeling 

 experienced when linen is just put on. But 

 though rapidly conducting the heat, it has little 

 capacity for moisture, and thus soon becomes 

 saturated, leaving the pores of the skin clogged 

 and obstructed, unless the garment be frequently 

 changed. Having little elasticity of fibre, it forms 

 a smooth and dense fabric, totally void of that 

 stimulating function often so much valued in 

 flannel. From the experiments of Count Rum- 

 ford, it appears that linen does not attract damp- 

 ness so readily as wool, hair, or other animal 

 substances ; nevertheless, when it is damp, it is 

 more prejudicial than these, and therefore requires 

 to be well dried and aired before being worn. 



Silk, as a non-conductor of heat, ranks next to 

 cotton ; but its qualities in this respect depend in 

 a great measure upon the kind of fabric into 

 which it is woven. Generally speaking, silken 

 fabrics are light and thin ; articles of luxury and 

 ornament rather than of everyday utility. Never- 

 theless, silk possesses several valuable hygienic 

 properties, of Which the most curious and least 

 -understood is that appertaining to its electric 



qualities. It is found (see No. 17) that on the 

 whole the state of the body when healthy and 

 vigorous \spositive, or that a surplus of positive 

 electricity tends always to appear on the surface, 

 from the actions of the vital organs ; but that, 

 after severe labour, hard exercise, and exhaustion, 

 the state of the free electricity generally changes 

 to negative. It is not improbable that when the 

 actions of electricity on the animal system are 

 better understood, it may be possible to use 

 artificial methods of maintaining, under all cir- 

 cumstances, the charge that is identical with 

 health and activity : we have acquired, by means 

 of our houses, clothing, and fires, a tolerable com- 

 mand of the element of heat ; and it is to be 

 hoped that we may some day attain an equal 

 command over the element of electricity, and 

 keep at a distance the deleterious negative charge 

 as effectually as we defy the winter cold. On this 

 important subject, so far as the influence of silk 

 which is an excellent non-conductor of electricity 

 is concerned, Drs Robertson and Carpenter 

 have the following interesting remarks, which we 

 transcribe at length : 



' However little or unsatisfactory our knowledge 

 of the operations of this remarkable agent in the 

 animal economy, there is no doubt that electricity 

 fulfils important and necessary purposes in the 

 living system, and that a certain amount of positive 

 or negative electricity is being constantly given off 

 from the surface of the body in greater or less 

 degree, according to sex, temperament, weather, 

 the nature of the clothing, &c. It has been said 

 that the skin and most of the internal membranes 

 are in opposite electrical conditions ; and, accord- 

 ing to a theory of Dr Wollaston, the existence of 

 free acid in the urine and gastric juice marks the 

 prevalence of positive electricity in the kidneys 

 and the stomach ; whereas the existence of free 

 alkali in the bile and the saliva indicates an excess 

 of negative electricity in the liver and the salivary 

 glands. Whether this view be tenable or not, it 

 seems that the living body is never in a state of 

 perfect electrical equilibrium with the substances 

 or bodies around it, unless it be maintained by 

 free contact with them ; and it is stated, in illus- 

 tration of this, that if two persons, both insulated, 

 join hands, sufficient electricity is developed to 

 influence the electrometer. Some electric disturb- 

 ance is manifested by almost every individual, if 

 it be carefully sought for. In men, it is most fre- 

 quently positive ; and irritable men, of sanguine 

 temperament, have more free electricity than those 

 of phlegmatic character ; whilst the electricity of 

 women is more frequently negative than that of 

 men. Some individuals exhibit these phenomer 

 much more frequently and powerfully than other 

 There are persons, for instance, who scarcely eve 

 pull off articles of dress which have been wor 

 next the skin without sparks and a crackling nois 

 being produced, especially in dry weather ; tl 

 may, however, be partly due to the friction of thes 

 materials on the surface, and with each other, 

 it has been proved to be greatly influenced 

 their nature. 



'The most remarkable case of the generatior 

 of electricity in the human subject at present or 

 record, is one that has been met with in Americ 

 (American Journal of Medical Science, January 

 1838). The subject of it, a lady, was for many 

 months in an electric state so different from that 



