Volume 1

The standard physician : a new and practical encyclopaedia of medicine and hygiene especially prepared for the household / edited by Sir James Crichton-Browne [and others].

Date:: 1908-1909

Credit: The standard physician : a new and practical encyclopaedia of medicine and hygiene especially prepared for the household / edited by Sir James Crichton-Browne [and others]. Source: Wellcome Collection.

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$THE STANDARD 1T S K' IA N Bleeding Blister o 7 1 BLINDNESS.—Term referring to tlie im.liility of an eve to jierceive light ; practically, however, the designation of “ blind ” is applied to indi- viduals whose sight is impaired to such an extent that they cannot find their way about. In most countries where vaccination is universally employed, the number of the blind has markedlv decreased. Wdiere this operation is not compulsory or is not used to any great extent, smallpox is the most frequent cause of blindness. At the jiresent time the most conimon cause of blindness among ci\u]ised peoples is the purulent, tir gonorrlia^al, conjunctivitis of the new-born. Hliudness niay come on at any time of hie, when the transparent jiarts of the eye become impervious to light as the result of extensive corneal cloudiness, closure ot the jiupil from inflammation of the iris, cataract, diseases of the letiiia and choroid, aflections ot the optic ner\’e, or severe injuries to the eye. Diseases ot the brain and spinal cord may also bring on blindness. As a general rule, cases of blindness which are congenital, or which are due to disease of the retina, the o]itic ner\'e, or the brain, must be looked upon as hoyieless. Partial blindness is a term ajiplied to that condition in which a portion, even one-half, of the visual held of one oi' both ('Ves is atlected, so that the patient is blind in sjiots {(iinhlynf^id) or sees only those objects which happen to come on either the right or the left side of the median line [hemianopsia). Such forms of blindness usually result from injury to the nervous elements of the eye. The term “ ])sychic blindness ” or “ mind blindness ” is ajiplied to a condi- tion in which, as the result of destruction of certain portions of the brain, the ])atient can still see, but is unable to interpret what he sees. BLISTER.—An effusion of serum underneath the superheial skin. It may be brought about by an irritating agent, extreme heat (as in a burn), extreme cold (as in freezing), or by a variety of other physical and chemical agents. Thus X-rays, the electric spark, radium, etc., can cause blisters on the skin ; or they may be produced by such substances as mustard, can- tharides, and similar j)harmaceutical agents. In medicine, blisters are most frequently produced by mustard, cantharides, turpentine, or l)y the actual cauterv. The chief action of a blister is as a counter-irritant. Whereas it is frequently believed by the laity that such blisters draw the morbid matter to the surface, and that thus the cause of an illness is removed, the true action is far different. It consists really in setting up a ner\'ous reflex action in the sympathetic nervous system. It has been established that practically every internal organ of the body has a representation in the superheial layer of the skin, and that influences acting on the organs may show themselves by changes of greater or less degree of dehniteness in these superheial, related areas. Conversely, irritations of these areas in their turn can bring about modiheations in the activity of the organs themselves, particularly in the matter of their blood supply. VOL. I. ^$