Yellow phosphorus is another poisonous substance which is employed in certain industries. It has been largely used in the manufacture of matches, but is now being gradually superseded by the less toxic, non-crystalline red phosphorus. The entrance of the fumes from these chemicals into the cavities of decayed teeth is apt to be followed by inflammation and necrosis of the jaw-bones, those of the lower jaw being destroyed more frequently than those of the upper. This severe disease is also attended with danger to life, and necessitates an operation which produces marked facial deformity. Sometimes there results extended and deep suppuration in the neck, and a general pTemia. Although many legal restrictions have been applied to the control of workers in match factories, cases of phosphorus-poisoning have been reported frequently. A definite result can be obtained only by entirely forbidding the use of the dangerous phosphorus. A new method has lately been devised by which matches may be made without the employment of this very toxic substance, and in this way a more favourable condition of affairs will undoubtedly be realised.
The fumes of mercury, if inhaled for a prolonged period of time, produce a chronic form of poisoning, to which workmen in mines and furnaces, mirror-makers, hatters, and makers of thermometers and barometers, are all exposed. The mercury is taken up through the mucous membranes, through Nvou nds , and even through the unbroken skin. The system does not, as sometimes stated, become accustomed to the effects of mercury, but the harmful consequences appear sooner in one workman than in another. A feeling of heat in the mouth, a metallic taste, and salivation are the pre monitory signs of chronic mercury-poisoning. Later on the gums become swollen, red, and sensitive, the teeth are loosened, and chewing becomes difficult. If the absorption of mercury continues, ulceration of the gums, and other parts of the mouth follows, and sometimes there is pronounced sloughing of the soft parts. In very severe cases the inflammation may extend to the jaw-bones, and result in their destruction. Gastric and intestinal disturbances arc usually present ; and in women there are frequently disorders of menstruation, and miscarriages. A peculiar tremor of the hands and arms, which may involve also the legs, the face, the larynx, and the tongue, is very characteristic. The general health is gradually undermined, the strength declines, and the face assumes a very languid expression.
The manner of coating mirrors, and the method of exhausting incan descent-light bulbs, have been so altered as to be no longer dangerous. It
now remains for science to devise some substitute for mercury in the remaining industries in which it is employed. Strange to say, it was among the mirror-coatcrs that it was found practical to eliminate the dangers of mercurial poisoning, by proper equipment of the workshops and changes in the methods of \vork, so that in this instance at least it would not have been essential to devise a substitute for the metal.
Workers in mercury, like those in lead, must observe extreme cleanliness. Workmen in the more dangerous branches should be selected Nvi t h particular reference to their general good health, and well-preserved teeth. As soon as the process of decay attacks even a single tooth, work should immediately be stopped. If it has been found necessary to extract the offending tooth, the person should not resume his original occupation until the \you nd in the gum has been completely healed.
Chromic acid and its salts give rise to a peculiar affection of the skin and mucous membranes. If the dermal covering is unbroken, the effect is exerted very slowly. The slightest abrasion, however, is rapidly followed by the formation of ulcers, \vhich quickly become deepened, and are cured \vith difficulty. Inhalation of the dust or fumes from chromic-acid salts causes severe irritation of the mucous membranes of the air-passages ; and in addition to the inflammation in the throat and an increased flow of tears. there is present a continuous tickling in the nose, which produces a constant desire to sneeze. Within a very few days particles of the nasal mucous membrane are thrown off with the dark discharge from the nose, although little pain may have been noted, and in a few weeks, sometimes even in less than one week, examination discloses a perforation of the cartilaginous septum of the nose. The outward form of the nose remains unchanged, because the bone and that part of the septum which is covered by the skin have not been attacked. Similar inflammations may involve also the larynx, or the bronchi and their branches.
Workmen engaged in handling .chromic acid must take care not to injure the skin of their hands or other parts of the body ; and even slight wounds must be carefully covered with a protective dressing. Careful washing of the hands and face and frequent irrigations of the nose are essential. The employer should provide a suitable means of getting rid of the dust which is produced, and prevent it from circulating in the workrooms.