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SCIENCE 



[N. S. Vol. XXVII. No. 699 



and weaving industries; the other is con- 

 cerned with those processes in which the 

 composition of matter is changed, chemical 

 manufacture, and includes metallurgy, 

 clay burning, glass making and the heavy 

 chemical industries. By far the greatest 

 number of industries partake of the nature 

 of both these branches— in other words, are 

 both mechanical and chemical— and in this 

 way chemistry has a greater or less im- 

 portance in connection with all industries. 

 Students of the development of the human 

 race find that the mechanical arts develop 

 first; but not long afterwards and long 

 before recorded history, are found evi- 

 dences of a knowledge of metallurgy and 

 of ceramics in the remains of iron and 

 bronze implements and of earthenware 

 utensils. Metallurgy and ceramics are 

 both chemical industries, and they both 

 presume a knowledge of chemical facts, 

 that is, they presiune a knowledge of the 

 properties of certain substances, the ores 

 in one case, clay in the other, and of the 

 changes in composition which tliose sub- 

 stances undergo. If we turn to ancient 

 Egypt, which is unique in having de- 

 veloped a somewhat advanced civilization 

 in an early period and in having preserved 

 by monument, picture, scroll and orna- 

 ment a record of that civilization, we find 

 that the people of that country, in addi- 

 tion to a knowledge of metallurgy and 

 ceramics, were also informed in the arts of 

 dyeing, pigment manufacture, varnish 

 making, plaster making, paper making and 

 the fermentation industries— all chemical 

 manufacture — and most interesting of all, 

 they were well versed in that distinctly 

 chemical and not altogether simple in- 

 dustry—glass manufacture. Five thou- 

 sand years ago they made a glass which 

 approximates closely in composition the 

 common glass, so-called soda-lime glass, of 

 to-day. Now glass making is interesting 

 from a number of standpoints. It did not 



develop as many other chemical industries 

 did, apparently, in a number of localities 

 widely separated, but in one, and that 

 Egypt, and thence it spread through- 

 out the world. So it is comparatively 

 easy to trace the spread and the growth 

 and the historical development of glass- 

 making. On the east the Babylonians, the 

 Assyrians, the Chaldeans, the Phoenicians 

 learned the art; on the north the Greeks 

 and Romans; China probably learned the 

 art from Egypt by way of Ceylon, to which 

 place adventurous merchants journeyed; 

 India learned it later; Byzantium learned 

 the art from Rome, and through Rome, 

 too, the knowledge filtered and spread into 

 Italy, beyond the Alps, and into the Rhine 

 country. In the seventh century the 

 Arabians, in their rise as a conquering 

 nation, overran Egypt, learned her arts 

 and carried the glass industry into Spain, 

 where it flourished. Finally the industry 

 centered in Bohemia, which is preeminent 

 in this industry to-day. And thus the his- 

 tory of glass making can be traced from 

 the most ancient times down to the begin- 

 ning of modern history. Nor is this all, 

 for in tracing the history of one chemical 

 manufacture, one inevitably comes in con- 

 tact with others. An industrial people is 

 seldom satisfied with one industry and so 

 where glass making fiourished, as a rule 

 other industries flourished also. Nobody 

 knows how glass making was fii'st dis- 

 covered. Ordinary glass is composed of 

 silica, lime and soda and can be made by 

 melting together sand, limestone and soda 

 in the proper proportions and at a suf- 

 ficiently high temperature. The Nile val- 

 ley is cut through limestone rock and this 

 is the common building stone of the region. 

 Soda occurs there, as it does in the arid 

 regions of this country, as an incrustation 

 on the surface of the soil — alkali, to use 

 the common expression; and sand is, of 

 course, abundant. It would be hard to 



