VIGNETTES OF FAMOUS SCIENTISTS
Louis Pasteur
He was one of the greatest biologists and pathologists
who ever lived. To him we owe millions of human lives.
The work of the celebrated French biological chemist and pathologist, Louis Pasteur, has given knowledge of the highest importance to nearly every branch of physical and natural science.
Pasteur was born December 27, 1822, at Dole, among the foothills of the Jura mountains in eastern France. Early in life he chose chemistry and medicine as the field he wanted to enter. He graduated from the Ecole Normale, Paris, in 1847. In 1848 he became professor of physics at Dijon and in the following year accepted the professorship of chemistry at Strassburg. He became dean and professor of chemistry in the faculty of sciences at Lille in 1854. He remained there until 1857, when he went to Paris as scientific director of the Ecole Normale Supérieure and was elected a member of the Institute. In 1863 he became professor of geology, physics, and chemistry at the Ecole des Beaux-Arts and from 1867 to 1889 he was professor of chemistry at the Sorbonne. A little later he founded and conducted during the balance of his active life, the Pasteur Institute; which became at once a very famous center of research in his particular line of investigation. He died near Saint-Cloud, September 28, 1895.
By his classical researches on optically active substances and their separation into isomeric modifications of identical chemical but different physical properties, Pasteur became the originator of the science of stereochemistry.
This naturally leads up to the study of the phenomena of fermentation and putrefaction, and their relation to the micro-organisms in the atmosphere. By passing a current of air through gun-cotton, and then dissolving the latter in alcohol, an insoluble residue is obtained which, under the microscope, is found to consist largely of mature and immature living germs.
In the field of fermentation and the germ theory his work was even greater. He showed that lactic, butyric, acetic, and other fermentations are caused by microorganisms, and established on a firm scientific basis the principle that spontaneous generation cannot take place, at least under ordinary conditions.
The study of such germs—a hitherto unknown field of life—occupied the remainder of Pasteur's days. The discoveries made therein by him, and by those who have followed in his steps, have profoundly affected individual humanity, and the industrial world. To mention a few of the most important will indicate the scope of his labors, and the gain that has resulted from them.
Pasteur's studies on the diseased conditions of wine and beer have rendered possible and easy the prevention of these conditions. No less important were his investigations on the silkworm's disease, pebrine, and its cure.
In discovering the bacterial cause of anthrax and splenic apoplexy in cattle, and of fowl cholera, and the remedies in each case, enormous annual losses in domestic animals has been prevented, and a system of animal vaccination worked out. This one discovery alone was epoch-making in the science of disease. He prevented the various diseases caused by septic bacteria by inoculating animals with a milder form of the disease by means of a weaker brood of bacteria artificially cultured. Pasteur found that by keeping a cultured crop of specific microorganisms at a certain temperature with a full supply of oxygen he could reduce organisms to an incapacity for producing spores, therefore to sterility. But before this point is reached the cultured organism loses its virulence, although still germinating; vaccination with it then produces a mild disease, which effectually protects from the fatal scourge of splenic fever, of fowl's cholera, and other diseases.
In the same manner, he dealt with splenic apoplexy, which he showed to be caused by the presence of specific bacteria in the blood. Pasteur's well-known treatment of hydrophobia is based on a similar principle, the spinal column of the infected animal serving as culture medium.
So numerous were the discoveries of this most noted physiologist in the domain of the micro-organisms, and so successful the remedies he devised to defeat or minimize their injurious action, that the terms pasteurizing, pasteurism and pasteurization as nouns, and the verb to pasteurize, together with similar words in all the modem languages of civilized people, have passed into common usage, to mean all preventative or prophylactic systems devised, either by him or since his time, to counteract the evil effects of those minute organisms which are always present in the purest air and the cleanest environment, and are ever ready to attack and destroy.
222
