A Handbook of Health by Woods Hutchinson (readnow TXT) 📕

The photograph shows work done in the Panama Canal Zone. The swamp has already been drained by ditches, and the work of destroying the larvæ is being completed by the use of oil.

This is usually done by closing up tightly the sick-room, putting into it all clothing, bedding, pictures, books, hangings, and other articles used during the illness (except wash-goods, which, of course, can be sterilized by thorough boiling; and dishes and table utensils, which also can be scalded and boiled); draping the carpet over chairs so as to expose it on all sides, opening closets and drawers, and then filling the room full of some strong germ-destroying fumes.

One of the best disinfectants, and the one now most commonly used by boards of health for this purpose, is formaldehyde—a pungent, irritating gas, which is an exceedingly powerful germ-destroyer. This, for convenience in handling is usually dissolved, or forced into water, which takes up about half its bulk; and the solution is then known as formalin.

When formalin is poured into an open dish, it rapidly evaporates, or gives up its gas; and, if it be gently heated, this will be thrown off in such quantities as to completely fill the room and penetrate every crevice of it, and every fold of the clothing or hangings. One pound, or pint, of formalin will furnish vapor enough to disinfect a room eight feet square and eight feet high, so the amount for a given room can thus be calculated. The formalin vapor will attack germs much more vigorously and certainly if it be mixed with water vapor, or steam; so it is usually best either to boil a large kettle of water in the room for half an hour or more, so as to fill the air with steam, before putting in the formalin, or to use a combination evaporator with a lamp underneath it, which will give off both formalin and steam. This, if lighted and placed on a dish in the centre of a wash-tub or a large dishpan, with two or three inches of water in the bottom of it, can be put into the room and left burning until it goes out of its own accord.

Another very good method is to take a pan, or basin, with the required amount of formalin (not more than an inch or two inches deep) in the bottom of it, get everything ready with doors and windows fastened tight and strips of paper pasted across the cracks, pour quickly over the formalin some permanganate of potash (about a quarter of a pound to each pound of formalin), and then bolt for the door as quickly as possible to avoid suffocation. The resulting boiling up, or effervescence, will throw off quantities of formaldehyde gas so quickly as to drive it into every cranny and completely through clothing, bedding, etc. The room should be left closed up tightly for from twelve to thirty-six hours, when it can be opened—only be careful how you go into it, first sniffing two or three times to be sure that all the gas has leaked out, or holding your breath till you can get the windows open; and in a few hours the room will be ready for use again.

Another older and much less expensive disinfectant for this purpose is common sulphur. From one to three pounds of this, according to the size of the room, is burned by a specially prepared lamp in a pan placed in the centre of a dishpan of water, and the vapor thus made is a very powerful disinfectant. This, however, is a very poisonous and suffocating gas (as you will remember if you have ever strangled on the fumes of an old-fashioned sulphur match) and, compared with formalin, is nearly five times as poisonous to human beings, or animals, and not half so much so to the germs. Where formalin cannot be secured, sulphur is very effective; but its only merit compared with formalin is that it is cheaper, and more destructive to animal parasites and vermin such as bugs, cockroaches, mice, rats, etc., when these happen to be present. Formalin has the additional advantage of not tarnishing metal surfaces, as sulphur does.

It is a good thing for every household and every schoolroom to have a bottle of formalin on hand, so that you may sniff the vapor of it into your nostrils and throat if you think you have been exposed to a cold, or other infectious disease, or make a solution with which to wash your hands, handkerchiefs, pencils, etc., after touching any dirt likely to contain infection. Half a teaspoonful in a bowl of water is enough for this. A saucerful of it placed in an air-tight box, or cabinet, will make a disinfecting chamber in which pencils, books, etc., can be placed over night; and a teaspoonful of it in a quart of water will make an actively germ-destroying solution, which can be used to soak clothing, clean out bedroom utensils, or pour down sinks, toilets, or drains. It is a good thing also to pour a few teaspoonfuls occasionally on the floor of the closets in which your shoes, trousers, dresses, and other outdoor clothing are kept, as these are quite likely to be contaminated by germs from the dust and dirt of the streets.

Formalin is one of the best and safest general disinfectants to use. Its advantages are, that it is nearly ten times as powerful a germicide as carbolic acid, or even corrosive sublimate, so that it may be used in a solution so weak as to be practically non-poisonous to human beings. It is so violently irritating to lips, tongue, and nostrils as to make it almost impossible for even a child to swallow it, while the amount that would be absorbed if taken into the mouth and spit out again would be practically harmless, so far as danger to life is concerned, though it would blister the lips and tongue.

Bacteria, our Best Friends. While, naturally, the bacteria that do us harm by producing disease are the ones that have attracted our keenest attention and that we talk about most, it must never be forgotten that they form only a very, very small part of the total number of bacteria, or germs. These tiny little germs swarm everywhere; and the mere fact that we find bacteria in any place, or in any substance, is no proof whatever that we are in danger of catching some disease there.

All our farm and garden soil, for instance, is full of bacteria that not only are harmless, but give that soil all its richness, or fertility. If you were to take a shovelful of rich garden earth and bake it in an oven, so as to destroy absolutely all bacteria in it, you would have spoiled it so that seeds would scarcely grow in it, and it would not produce a good crop of anything. These little bacteria, sometimes called the soil-bacteria, or bacteria of decay, swarm in all kinds of dead vegetable and animal matter, such as leaves, roots, fruits, bodies of animals, fishes, and insects, and cause them to decay or break down and melt away. In doing this they produce waste substances, particularly those that contain ammonia, or nitrates, or some other form of nitrogen, which are necessary for the growth of plants or crops.

This is why soil can be made richer by scattering over it and plowing into it manure, waste from slaughter houses, or any other kind of decaying animal or vegetable matter. This is promptly attacked by the bacteria of the soil and turned into these easily soluble plant foods. The roots of the plants grown in the soil could no more take this food directly from dead leaves or manure than you could live on sawdust or cocoanut matting.

So, if it were not for these bacteria, or lower plants, there could be no higher, or green, plants. As animals live either upon these green plants, such as grass and grains, or upon the flesh of other animals that live upon plants, we can see that without the bacteria there would be no animal life, not even man. No bacteria, no higher life. It would be safe to say that, out of every million bacteria in existence, at least 999,999 are not only not harmful but helpful to us.

One large group of bacteria produces the well-known souring of milk; and while this in itself is not especially desirable, yet the milk is still wholesome and practically harmless, and its sourness prevents the growth of a large number of other bacteria whose growth would quickly make it dangerous and poisonous. Many races living in hot countries deliberately sour all the milk directly after milking, by putting sour milk into it, because, when soured, it will keep fairly wholesome for several days, while if not soured it would entirely spoil and become unusable within twenty-four hours.

Another group of bacteria, which float about in the air almost everywhere, are the yeasts, which we harness to our use for the very wholesome and healthful process of bread-making. Millions upon millions of bacteria of different sorts live and grow naturally in our stomachs and intestines; and while they are probably of no special advantage to us, yet at the same time the majority of them are practically, within reasonable limits—not to exceed a few billions or so—harmless.

Insect Pests. One kind of "dirt" that should be avoided with special care is insects of all sorts. No one needs to be told to try to keep a house, or a room, clear of fleas, bed-bugs, or lice; indeed to have these creatures about is considered a mortal disgrace. Not only is their bite very unpleasant, but they may convey a variety of diseases, including plague and blood poisonings of various sorts. But there is another insect pest far commoner and far more dangerous than either fleas or bed-bugs,