238 MODERN SCIENCE READER 



to be of little practical value when first performed and 

 results that, from the industrial point of view, are of the 

 highest value. 



I have often been embarrassed by these questions put 

 to me in my laboratory: ''What are you doing?" and "Of 

 what use is the work?" Generally I am obliged to answer 

 to the first, "I regret that I cannot possibly explain what 

 I am doing. I have tried to do so in some cases, but I 

 have been begged to stop"; and to the second, the only 

 possible answer has been, "I do not know." I am well 

 aware that such answers seem to show that the work is in 

 fact of no value, and that this is the impression that my 

 visitors carry away with them. Now I do not propose to 

 try to justify my own work, nor to try to explain it. For 

 the most part it has had to deal with matters that do not 

 touch our daily lives, and therefore it cannot be made inter- 

 esting, not to say intelligible. I shall, to be sure, show you 

 how one piece of work carried out twenty years ago has 

 become of world-wide interest, though when it was carried 

 out it appeared as little likely to be of practical value as 

 anything ever done. But this is anticipating. 



During the latter half of the eighteenth century there 

 lived in Sweden a poor apothecary who, in his short life, 

 probably did more to enlarge our knowledge of chemistry 

 than any other man. Throughout his life he had to contend 

 with sickness and poverty. He was obliged to carry on the 

 business of an apothecary in order to keep the wolf from 

 entering his house he never succeeded in keeping it from 

 the door. His great delight was to investigate things 

 chemically, and to find out all he could about them. It is 

 simply astounding to the chemist to find how many dis- 

 coveries of the highest importance he made. But I have 

 not mentioned his name. I refer to the immortal Scheele. 

 He died in the year 1786 at the age of 43, yet he will al- 

 ways be remembered, and those who know most of the 

 work he did will respect him most. 



Though Scheele was an apothecary, his chemical work 



