240 DR. ARTHUR RANSOME ON THE 



Organic Matter in the Atmosphere. 



Before considering the nature of the organic matter to 

 be found in human breath, it may be well to advert briefly 

 to the prior question of the amount and kind of organic 

 matter in the air breathed. 



There has lately been much discussion as to the priority 

 of the discovery of organic matter in both fresh and re- 

 spired air; and yet it is certain that, from very early 

 times, men have recognized the fact that the air is the 

 vehicle of many substances both organic and inorganic. 

 The old writings are full of disquisitions upon the teem- 

 ing air. 



Boerhaave calls it the " instrumentum catholicum/' and 

 speaks of the ^^ corpuscula quae in aere perpetuo obvolitant/^ 

 and he shows how " terra tota ex aere cadentia recipit 

 omnia, ita rursum aer de terra universa accipit. Fitque 

 inter bina hsec perpetua quasi omnium revolutio, distillatio 

 assidua.'^ — Elementa Chemus (Leyden, ed. 1732), p. 484. 



Medical men also, from the time of Hippocrates, have 

 been only too prone to ascribe all kinds of diseases to the 

 constituents of the atmosphere. Sydenham says, " Since 

 it is the will of God, the Supreme Arbiter and Regulator 

 of all things, that the human frame be by nature adapted 

 to the reception of impressions from without, it follows 

 that it must also be liable to a variety of maladies. These 

 arise partly from the particles of the atmosphere, partly 

 from the different fermentations and putrefactions of the 

 humours. The first insinuate themselves amongst the 

 juices of the body, disagree with them, mix themselves 

 up with the blood, and finally taint the whole frame with 

 the contagion of disease.^' — Med. Obs. Sect. I. chap. i. 



In recent times also, the fact of the presence of organ- 

 isms in air has been fully recognized. 



The great controversy which has now been going on for 



