Page:Popular Science Monthly Volume 47.djvu/114

106, a fungus allied to the microbes. Since then it has been enough to sow the tubs in which the fermentation proceeded with the pure Aspergillus to obtain a better return and an opium of superior quality in only one or two months.

In the preparation of several most indispensable alimentary products certain micro-organisms, domesticated as it were, prove themselves incomparable chemists. Without them these preparations would be impossible. Among such products are bread, alcohol, wine, beer, and such fermented substances as koumiss, cheese, and sauerkraut.

These microbes are inferior algæ formed of one cell, usually with an envelope. They live almost everywhere on and with living beings, in the ground, in water, on solids, etc., and multiply with extreme rapidity. They produce a great variety of actions, some of which, as we have seen, are beneficial, while others are injurious.

As microbes decompose dead matter, so they are capable of disorganizing living matter. Some species have this power in a marked degree, which is distinguished as virulence. They are called pathogenic microbes, which means capable of causing illness. Each species of pathogenic microbe produces a particular kind of disease, and has a power that varies considerably according to a number of circumstances. The microbe alone, however, can not produce disease: that requires the intervention of the organism of the subject in which the disorder is to be developed. The disease is, in fact, the resultant of the reaction of the one upon the other of the two factors, the microbe and the organism. According to the felicitous comparison of Prof. Bouchard, the organism is a strong place, the microbe is its assailant, and the struggle between them is the infectious disease. The condition of the organic estate which the microbe endeavors to seize is therefore important. If the person is in general good health, he will offer a vigorous resistance to the microbes. If, on the other hand, his health is not perfect, there will be a point where the defenses are weak, and his danger will be proportionately great; for, as M. Bouchard said some time ago, one does not become ill till he is already not in good health. There are many ways of getting into poor health. It may be done by a number of processes, which may be summarized under the two categories of troubles of the organic functions or lesions of the tissues. Some of these pathogenic processes depend directly on a variety of social influences.

Wealth and poverty are alike efficient factors of disease. The rich man, by his often superabundant diet, his neglect of exercise, and his excess of luxury, readily contracts obesity, gout, or diabetes; his kidneys and his heart are frequently afflicted with