30 



noxious, and even destructive. BEDDOES cm- 

 ployed in his experiments HUMPHRY DAVY, a 

 young man of promising genius, who has since far 

 surpassed his instructor in celebrity and merit. DA- 

 VY discovered the intoxicating* power of the nitrous 

 oxyd gas, and shewed, that it was absorbed, during 

 respiration, by the blood, to which it imparts a 

 purple colour, and extricates from it part of the 

 gases it had formerly absorbed. He afterwards 

 extended his experiments to respiration in atmos- 

 pheric air ; and it appeared to him, that the blood 

 actually absorbed part of the nitrogene in the air, 

 so that about three or four cubic inches were ab- 

 sorbed every minute. HENDERSON and PFAFF 

 repeated his experiments with similar results ; & 

 mistake, however, has since been discovered in 

 these experiments, in consequence of not being ac- 

 quainted with the laws, which regulate the mix- 

 ture of gases with liquids. About this time, how- 

 ever, they were discovered by JOHN D ALT ON, 

 an ingenuous natural philosopher, who soon after- 

 wards published his experiments. One of these 

 rules is, that, when a liquid comes in contact with 

 a gas, it absorbs a determined proportion of the 

 gas ; and if it then comes in contact with another 

 gas, it absorbs also a quantity of that, but emits, 

 at the same time, a part of what it had absorbed 



