The 



arly not 



ponent fluids of the air they called them ghosts. The term has 

 persisted to this day, only we translate the German Gahst or 

 Geist, by gas, and speak of the various gases of the air. 



We are indebted to Van Helmont for the first experimental 

 knowledge of the nature of air, and of the relation to it of plants 

 He is one of the most peculiar figures which the history of sci- 

 ence presents to us. Born (in 1577) in an epoch of transition, 

 he formed, says Claude Bernard, the connecting link between 

 the mystic savants of the middle ages and the modern experi- 

 mentalists. 



As many of his biographers recall, Van Helmont possessed 



i the first t 

 researches, 

 tion for the 



t that 



This 



nt consisted in effecting the 

 rbon. After the carbon had 



ned there remained only one pound of ashes, 

 ncluded that 68 pounds of carbon had beenconve 

 isible air, which he called the gas, or spirit of 

 was he who discovered the property of this gs 



and in air that will not support respiration or c 



bustion 



. It was the gas which 



to day we 



call 



carbon 



dioxi 



the disc 



:overy of which is thus d 



ue to him. 



Va 



n Helm 



lont d 



in 1644 



.. He was the last of the 



alchemists 









Notw 



withstanding the example 



of Van He! 



Imont 



:, the w 



orld v 



slow in 

 to disci 



adopting the experiments 

 uss what they thought w; 



il method. 



Scie 

 'hat c 



mght t. 



:t l 



