THE ALUMNI JOURNAL 23 



peraUire of — I40°C\ ol)tained by means of liquid sulphurous and 

 carbonic acid." The patient Dewar succeeded in securing- obstinate 

 hydrogen not only in a liquid but even in a solid state. Mighty 

 deeds; Scheele's heart would ha\e leaped at them, but he never 

 knew- 



Nor did he e\er know that urea, an organic body, could be pro- 

 duced artificially in a laboratory^ 



Scheele had not the hundredth part of the delicate and intricate 

 instruments with which the chemist of to-day is supplied His 

 apparatus was of the crudest sort, and much of it he was compelled 

 to manufacture himself. He never saw a polariscope, or a balance 

 which weighed a pencil-mark. Had he seen a laboratory like Sir 

 William Ramsay's, his actions would have resembled those of his 

 great countryman. Linnaeus the Botanist, when he first spied au 

 English wild-flower, — the earth would have felt his knees. 



When we remember these hardships and at the same time recall 

 the immense amount of valuable work he accomplished, we realize 

 what manner of man was Scheele. The pioneer who blazes the trail 

 in an unknown forest, surely deserves as much credit as he who 

 comes leisurely after and helps to widen the already-made ])ath. If 

 the second is the more cultured of the two, he is the less original. 



Because of Scheele's devotion to it, mention must here be made 

 of one of the most interesting hypotheses that ever entered into the 

 history of chemistry — the Phlogistic theorv. This doctrine which was 

 introduced by Johann Joachin Becher (1635-1682), and cham])ioued 

 by George Ernst Stahl (1660-1743) had special reference to the al- 

 terability of substances by fire. Its essential feature consisted in 

 assuming that all matter which could burn was a comjiound, con- 

 taitiing at least two constituents. On combustion, one of these 

 remained behind and one escaped. The element which remained 

 was named calyx, the [principle which disappeared was called phlo- 

 giston. It corresponded somewhat to the "celestial heat" of earlier 

 chemists. Since this Phlogiston existed in all condjustible sub- 

 stances and alwa\s vanished on heating, it was belie\ed that every 

 time a substance Avas burned it grew lighter. 



In due time it began to be pointed out that some substances when 

 heated, instead of becoming lighter, become hea\ier, and that often 

 the products of combustion weigh more than the substance burned 

 !t was shown that when zinc is burned, it changes into a white 

 t)Owder \\hich is heavier than the original metal. 



