1 96 Historical 



which makes me think that the distress one feels from it comes from 

 the quality of the air one breathes there. (P. 87.) 



When one thinks that these lines were written at the end of 

 the sixteenth century, three hundred years before Lavoisier and 

 Priestley, by a man whose specialty was not the study of the 

 chemical and natural sciences, one is filled with admiration for 

 the great astuteness of the learned Jesuit and the unusual accuracy 

 of the expressions he uses. Let us remember also that the pneu- 

 matic machine had not been invented, and that Torricelli had not 

 yet been born, when Acosta said that "the element of the air is 

 in this place so thin and so delicate that it is not proportioned 

 to human breathing". 



It is interesting to compare the explanations of Acosta with 

 what the celebrated Francis Bacon - wrote thirty years later on the 

 same subject, in his Novum organum (appeared in 1620). If I am 

 not mistaken, the comparison is not to the advantage of the 

 learned chancellor of Verulam: 



The rays of the sun produce no heat in what is called the middle 

 region of the air; which is explained well enough in the schools by 

 saying that this region is not near enough to the sun from which the 

 rays emanate, nor to the earth which reflects them. To support this 

 explanation, we may cite the summits of mountains (unless their ele- 

 vation is not great) where perpetual snows lie. In fact, certain 

 travellers have noticed that there is no snow on the summit of the 

 Peak of Teneriffe, nor on the Andes of Peru, whereas the sides of 

 these mountains are covered with it up to a certain height. It is 

 stated, moreover, that at these extreme heights the air is not cold, but 

 merely rare and sharp; that is why on the Andes it attacks and injures 

 the eyes and the stomach, which cannot keep food down. The ancients 

 had already noted that on the summit of Olympus the air was so rare 

 that to climb to it one must take with him sponges wet with vinegar 

 and water, and often place them on the nostrils and the mouth, since 

 the air, because of its rarity, did not suffice for respiration. It is 

 added that on this same summit, where neither rain nor snow- fell, 

 and where the wind never blew, there reigned such a calm that when 

 sacrificers had traced with their fingers characters on the altar of 

 Jupiter with ashes of the victims, these impressions remained quite 

 intact until the following year. Even today the travellers who ascend 

 to the summit of the Peak of Teneriffe make their ascent by night 

 and not by day; immediately after sunrise, their guides urge them to 

 descend without delay, apparently because of the danger caused by 

 breathing an air so rare and asphyxiating. 



In fact, it was not until a half century after Acosta, that 

 Torricelli invented the barometer, and Otto de Guericke the 

 pneumatic pump. After that, laboratory experiments could go 



