ix] Doctrines of Respiration. 229 



by Borelli, which taught that the air, still retaining its elasticity, 

 produced its effect on the blood in a physical manner, by exciting 

 vibrations for instance. He mentions the various forms of the 

 spiritual hypothesis, according to which either an actual vital 

 spirit, or some active particles, spirituous or ethereal, passed 

 from the air into the blood and gave it its vital properties. He 

 adds, " Some indeed while refusing to admit in plain terms that 

 "any actual spirit is generated out of the air, nevertheless 

 " affirm that a vital entity of some kind is taken up from the 

 "air, and indeed men, wholly opposed to the vitalistic sect" 

 (referring to the passage of Boerhaave quoted above) "have 

 " not shrunk from this view." He next refers to the chemical 

 hypothesis, namely, that some chemical substance, a saline 

 vapour, or an acid volatile salt, or aereal nitre, passed from 

 the air into the blood and produced an effect on the blood 

 through chemical processes ; and he places the views of Mayow 

 on the same level as those of the many other chemical authors. 



Discussing and rejecting all these various views, giving his 

 reasons for thinking that elastic air does not pass into the 

 blood, and refuting at some length the hypothesis that the 

 inspired air, through being cold, leads to a condensation of the 

 blood in the lungs, Haller warns the reader that the rejection 

 of all these views "does not lead to the conclusion that in 

 " breathing we derive nothing from the air." 



He argues that since air exists in such quantity in all the 

 humours of the body and since a ready entrance of air is afforded 

 by the absorbing veinlets surrounding the pulmonary vesicles 

 full of air, air does enter the blood, but " in the lungs loses its 

 " elastic nature and so becomes readily soluble in water and 

 " vapour. Hippocrates counted air as a nutriment of the body, 

 "and since even the most solid parts of the body contain a 

 " great deal of air and give that up when they are dissolved 

 " and reduced to their elements, it is extremely probable that 

 "air plays the part of a cement holding together the earthy 

 " elements." 



Such is Haller's account of pulmonary inhalation, and he 

 completes the story by an account of pulmonary exhalation, 

 which he says consists chiefly of water but not mere water, 



