710 TRANSACTIONS OP THE AMERICAN INSTITUTE. 



the amount of ozone at Torquay, he recounted the results of an 

 examination of the air exhaled by growing plants. Dr. Danbeny 

 found, in thirty-two instances out of fifty-seven plants experimented 

 upon; sensibly larger amounts of ozone in such air than in the 

 surrounding atmosphere, and he was therefore led to the conclu- 

 sion that the generation of ozone in the process of vegetation was 

 one of the appointed means of nature for the purification of the 

 air, and that not only Avere plants useful in restoring the equilibrium 

 of the atmosphere, but that they took an active part in the destruc- 

 tion of pernicious organic compounds given off either in the pro- 

 cess of decay, or by the Vv^aste of animal organisms. More ozone 

 w^as found near the sea than at inland localities ; a greater amount 

 in the country than in the towns ; and, lastly, more outside of a 

 building than in its inhabited rooms. The outbreak of epidemics 

 was often ascribed to the deficiency of ozone in the atmosphere, 

 but he had no evidence on that point. The action of hydro- 

 carbons — which, by uniting with oxygen, furnish indications of 

 ozone — had in his experiments been guarded against by removing 

 the test-paper to a greater distance, in the case of plants exhaling 

 aromatic odors, some of v/hich had been examined, he had also 

 found it necessary to discard altogether the use of India rubber 

 tubes for. connecting the parts of the apparatus, since it quickly 

 destroyed every trace of ozone. After the reading of Dr. Dau- 

 beny's paper, Dr. Gilbert referred to other statements made in 

 relation to the generation of ozone by vegetation, and expressed 

 the opinion that further evidence was required to establish the 

 identity of the ozone-like emanations of growing plants, and the 

 odorous substance produced during the slow combustion of phos- 

 phorus in moist air. 



After the reading of these items, an interesting discussion took 

 place on the first item, relative to action of belladonna when exter- 

 nally applied. Dr. Vanderweyde explained its action when taken 

 internally, and its peculiar eflect upon the pupil of the eye. He 

 said it was sometimes used l)y ladies to produce brilliancy of the 

 eyes. Drs. Stevens, Bradley, Feuchtwangcr, Richards, Hallcck, 

 Messrs. Bartlett, Eeid and Msvynard took part in the discussion. 

 It was generally conceded that belhidonna, like opium, to])acco 

 and other strong narcotics, when externally applied in large quan- 

 tities, was poisonous. 



The item on graphite also brought out considerable discussion 

 as to its origin, and the quality of that found on this continent. 



