THE AGE OF SCIENCE 241 



familiar chlorine as we can give to-day. The investigation 

 is a model. It could not have been accomplished without 

 the enthusiasm, the patience, the knowledge and the skill 

 possessed by Scheele. No ordinary chemist would have 

 been equal to it. We shall not overstate the case if we say 

 that Scheele 's discovery of chlorine ranks with the most 

 important and the most valuable of chemical discoveries. 

 That of oxygen outranks it certainly, but chlorine falls in 

 line not far behind. 



Now, why was this an important and a valuable dis- 

 covery? Primarily because it, like the discovery of 

 oxygen, though to a less degree, aided chemists in their 

 efforts to understand chemistry and thus to put them in a 

 position to deal more intelligently with chemical problems 

 of all kinds. That statement may, once for all, be made 

 of every important chemical discovery. But while Scheele 

 had no thought of any practical uses to which chlorine 

 could be put, and his discovery was not at first regarded 

 as one with a practical bearing, it proved eventually to be 

 of the highest practical value, and to-day it plays an 

 exceedingly important part in practical affairs. As is 

 well known, chlorine is the great bleacher, and as such is 

 used in enormous quantity, especially for bleaching straw, 

 paper and different kinds of cloth. As it would be ex- 

 pensive and inconvenient to transport a gas, and especially 

 such a gas as chlorine, it is locked up, as it were, by causing 

 it to act upon lime, and the " chloride of lime" or "bleach- 

 ing powder" thus formed, which readily gives up its 

 chlorine, is a most important article of commerce, many 

 thousands of tons being manufactured annually. Then 

 again chlorine is one of the most efficient disinfectants, 

 and as such it is finding more and more extensive use every 

 year, and is plainly contributing to the welfare of man by 

 interfering with the spread of disease. Further, it is 

 essential to the manufacture of chloroform, and that this 

 calls for a large quantity of chlorine will appear when it 

 is stated that nearly nine tenths of the weight of chloro^ 

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