BY J. JAMIN,
Of the French Academy.
In the interval between 1602 and 1626 four philosophers were born who seem to have been divinely appointed to teach men the mysteries of air. These were a German, Otto von Guericke (1602); two Frenchmen, Mariotte and Pascal (1620, 1623), and finally an Englishman, Boyle (1626). Pascal conceived the idea that air being material must have weight like other materials, and consequently that the earth must be pressed upon by its atmospheric envelope, and he proved this by the celebrated experiment at Puy de Dôme.
Soon after, Otto von Guericke, having invented the air pump, succeeded in exhausting the air from a vessel and confirmed Pascal’s idea that air was really heavy, while Mariotte and Boyle at the same time, each in his own country, and by almost identical experiments, proved that air is elastic, that its volume decreases by pressure, and generally in proportion to the weight to which it is subjected. Mariotte modestly called this discovery a rule of nature. We call it a physical law, and very suitably name it in France “Mariotte’s Law,” and in England “Boyle’s Law.”
It seemed necessary for science to collect her thoughts after this great achievement. She seemed to think there was nothing more to discover. Boyle and Mariotte would have been very much astonished if some one had told them that this air, whose properties they had been demonstrating, could be reduced to a liquid like water, and even to a solid like snow. Nearly two centuries passed before the world was prepared for this new discovery. We ourselves were ignorant of it until the month of April, 1883, when the Academy of Sciences received from Cracow these two dispatches:
“Oxygen completely liquefied; the liquid colorless as carbonic acid.” (April 9th.)
“Nitrogen frozen, liquefied by expansion; the liquid colorless.” (April 16th.)
Wroblewski.
Thus air has been reduced to a volume a thousand or fifteen hundred times less than under ordinary conditions. It ceased to be a gas and took the appearance of water. This astonishing result is only the last in a long list of experiments which for a long time were fruitless; it is the finishing touch to a building begun long ago, and on which many workmen have labored. What has been the work of each of them? It is a long story.