Page:Popular Science Monthly Volume 83.djvu/34

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30
THE POPULAR SCIENCE MONTHLY.

spread until the whole substance succumbs to the disease. Results of the tin pest are frequently found in museums. A tin vase in the British Museum which was found in Appleshaw, Hampshire County, England, and which dates back to 350 B.C. shows very strikingly the effects of the tin disease. The metal is not corroded, but it is dull in color and is so brittle that it can be broken with the fingers. Some of the fragments on being melted gave white tin with its original toughness and luster.

Fig. 10. A Two-hundred-year-old Medal that is Suffering from the Tin Disease.

Every one who has studied the advance of science during the last few centuries realizes that our modern inventions and processes of manufacture have been in many cases foreshadowed in the ancient world. The use of gunpowder by the Chinese and their extraordinary success with glazes, as well as the perfection obtained by certain of the old civilizations in the use of cements, pigments, dyestuffs and in metallurgical processes, is familiar to every one. What the modern scientist discovers by painstaking investigation was learned in those days either by accident or as the result of centuries of experience. Consequently the fact that the tin disease was known in those days ought not to be surprising. Professor Cohen has pointed to an observation of Aristotle.