30 THE POPULAR SCIENCE MOXTIILY 



spread until the whole substance succumbs to the disease. Eesults 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 wliite tin with its original toughness and luster. 



FlU. lU. A TWO-IIU.NDHKD YEAU-OLD MEDAL THAT IS SUFrEKING 



FROM THE Tin Disease. 



Every one who has studied the advance of science during the last 

 few centuries realizes tliat our modern inventions and processes of 

 manufacture have been in many cases foresliadowed in the ancient 

 world. Tlie use of gunpowder by tlie Chinese and thoir 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 metal- 

 lurgical processes, is familiar to every one. What tlie 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 Colioii lias pointed to an observation of Aristotle. 



