518 



SCIENCE 



[N. S. Vol. XXXIII. No. i 



alloys of copper first with tin and later 

 with zine, for many purposes, including 

 tools and implements. But because copper 

 and copper alloys were used for imple- 

 ments subjected to rough usage, this does 

 not justify us in concluding that the ma- 

 kers had knowledge of a method for ma- 

 king the metal hard, durable and service- 

 able. The simple and direct explanation 

 is that they had no better material for the 

 purpose at their command, just as in the 

 bone and stone periods bone and stone 

 were the best materials of construction 

 available for tools and implements. There 

 is no justification for the idea that ancient 

 peoples knew how to harden copper by 

 means unknown to metallurgists of the 

 present day. 



The ceramic arts are among the oldest 

 known to mankind and the earliest de- 

 velopment of them will probably remain 

 unknown to us. They had their beginnings 

 in the bone and stone age, and were prob- 

 ably first practised by women, not by men. 

 The first clay vessels may have been clay- 

 covered baskets dried in the sun — we do 

 not know certainly. From those early be- 

 ginnings to the highest types of the art 

 required the labor of many potters, num- 

 berless experiments and numberless fail- 

 ures. "We class ceramics among the chem- 

 ical industries, and properly so ; and yet the 

 ceramic art originated, developed and 

 flourished in many ages and in many parts 

 of the earth without any thought of or aid 

 from the science of chemistry. It has al- 

 ways been and still is to a very large ex- 

 tent an empirical industry. The essential 

 difference between the pottery practise of 

 ancient times and the most scientific prac- 

 tise of modern times lies in the reproduci- 

 bility of bodies and glazes by modern 

 methods. And yet few chemists in the in- 

 dustry have the temerity to predict how a 

 new clay or glaze will come out of the 



kiln. The potters of long ago, by countless 

 trials of different materials and countless 

 failures, were able to produce certain ef- 

 fects; and they were able to continue the 

 manufacture of similar wares and produce 

 similar effects so long as they were able to 

 obtain materials from the same sources. 

 A change of material would almost cer- 

 tainly mean a change in product. It must 

 not be forgotten that this same limitation 

 affects the ceramic industry to-day to a 

 very large extent. The varieties and prop- 

 erties of clays are almost numberless. It is 

 true that potters of all times have been able 

 to devise certain simple tests whereby they 

 have been able to recognize differences and 

 similarities in their raw materials, but 

 these tests were usually of too crude a 

 character to make refined distinctions. 

 Now from the very fact that ancient pot- 

 ters were dependent on certain sources of 

 supply for materials to produce certain 

 wares, it was very natural that wares made 

 by a certain people at a certain time were 

 not made by that people at another period, 

 or by different peoples. And such a case 

 would probably be classified as a lost art. 

 But this can not properly be called a lost 

 art. Rather it is a case of lost materials! 

 Given the materials, the wares could be 

 made as at first. This in fact has been the 

 work of more recent times — to ascertain 

 by careful analysis the nature of various 

 bodies and glazes and reproduce them. Of 

 course the composition is not the whole- 

 secret, the heat treatment is almost equally 

 important, and this is a matter for careful 

 physical testing. But as the result of mod- 

 ern research and practical experiment it 

 can scarcely be maintained that any body 

 or glaze exists which has not been and can 

 not be reproduced. 



Glass manufacture is allied to the- 

 ceramic industry, and is probably the out- 

 growth of it. In spite of Pliny's fable to 



