vn] of the Seventeenth Century. 185 



a mixture of two or more things, though it was admitted that 

 iu the atmosphere there existed besides the air proper, or pure 

 air, suspended as it were in this, a number of particles of a 

 different and probably varied nature. 



Both Lower and Borelli seem to have thought that it was 

 the air proper, and not any special particles in it, which passing 

 into the blood brought about the change of colour. Hooke, in 

 his Micrographia in 1607, treating of charcoal and speculating 

 concerning flame, propounds the view that it is due to action of 

 a part of the air which he calls a 'menstruum,' " a substance 

 " inherent in and mixt with the air, that is like, if not the very 

 " same with that which is fixt in Salt-peter." But he does not 

 go beyond this, and does not apply the same view to breathing. 



It was left for a countryman of Lower, for one belonging as 

 he did to the University of Oxford, to take the next step in 

 the physiology of respiration and to bring forward reasons for 

 thinking that in breathing only a part of the air, not the whole 

 air, not the air proper, was taken up into the blood. 



John Mayow, comkig like Lower of a Cornish family, was 

 born in London in 1643, the year before van Helmont died. 

 Admitted a scholar at Wadham College, Oxford, he became in 

 due time a Fellow of All Souls. Devoted as he was to science, 

 physic was not his profession; he took a degree in law "and 

 " became rioted for his practice therein, especially in the summer 

 " time at Bath." Yet to judge from his works one would 

 have thought that the whole of his time at Oxford had been 

 given up to continued research. In 1668, just four years before 

 Sylvius's death, he published, while as yet a young man of 

 twenty-five years, a little work containing four tracts, (1) Be 

 sal nitro et spiritu nitro aereo, (2) Be respiratione, (3) Be re- 

 spifatione foetus in utero et ovo, (4) Be motu musculari et 

 spwitibus animalibus. He eventually migrated to London and 

 in 1678 was admitted a Fellow of the Royal Society. In the 

 following year he died in Covent Garden at the all too early 

 age of thirty-five, " having been married a little before not 

 "all together to his content." 



Mayow's contribution to our knowledge of respiration was 

 this. He shewed that it was not the whole air which was 



