AND LABORIOUS OCCUPATIONS, &c. 41

rendered unfit for expanding the lungs sufficiently, and answeringthe other important purposes of respiration. Hence proceed asth-mas, coughs, and pulmonary complaints, so incident to personswho follow these employments.

To prevent such consequences as far as possible, the placeswhere these occupations are carried on ought to be constructed ineuch a manner as to discharge the smoke and other exhalations,and admit a free current of fresh air. Such artists ought neverto continue long at work ; and when they give over, they shouldsuffer themselves to cool gradually, and put on their clothes beforethey go into the open air. They ought never to drink large quan-tities of cold, weak, or watery liquors while their bodies are hot,nor to indulge in raw fruits, salads, or any thing that is cold onthe stomach.*

Miners, and all who work under-ground, are likewise hurt byunwholesome air. The air, by its stagnation in deep mines, notonly loses its proper elasticity, and other qualities necessary forrespiration, but is often charged with such noxious exhalations asto become a most deadly poison.

The two kinds of air which prove most destructive to miners,are what they call the fire-damp, and the cfioak-damp.f In bothcases the air becomes a poison by its being loaded with noxiousgas.| The danger from the former may be obviated by makingit explode before it accumulates in too great quantities ; and thelatter may be generally carried off by promoting a free circulationof air in the mine.

Minefs are not only hurt by unwholesome air, but likewise bythe particles of metal which adhere to their skin, clothes, &c.These are absorbed, or taken up into tl' j body, and occasion pal-eies, verJgoes, and other nervous affections, which often provefatal. Lead, and several other metals, are likewise very perni-cious to the health.

Miners ought never to go to work fasting, nor to continue toolong at work. Their food ought to be nourishing, and their liquorgenerous : nothing more certainly hurts them than living too low.They should by all means avoid costiveness. This may either bedene by chewing a little rhubarb, or taking a sufficient quantityof salad oil. Oil not only opens the body, but sheathes and de-fends the intestines from the ill effects of the metals. All whowork in mines or metals ought to wash carefully, and to changetheir clothes as soon as they give over working. Nothing would

* When persons heated with labour, have drunk cold liquor, they ought to continueat work for some time after.'

t These are the names by which miners distinguish damps. The choak-damp ex-tinguishes their candles, hovers about the bottom of the mine, and, for the most partconsists of carbonic acid gas. Fire-damp or hydrogen gas, occupies the superior spa-ces of the mine, and does great mischief by exploding whenever it comes in contactwith their lights. To subdue this gigantic power, which caused such mutilation anddestruction among the miners, by the tremendous explosions that so frequently oc-curred, was the task which Sir Humphrey Davy assigned to himself, and which, hadhis genius been baffled, the kingdom could scarcely have hoped to have seen it achiev-ed by another. This, however, he was enabled to overcome : and the Safety Lamp,which goes by his name, will remain to after-ages a testimony of his enlightened gen-ius, to which mankind are so infinitely indebted.

t See ¿JSrial Poison, under Poisons.