632 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



the poisonous action of the Calabar bean (physostigma). 

 When closes of atropia were given a few minutes before or 

 after taking the bean, animals recovered from the eifects, 

 which would otherwise have proved fatal, the niost success- 

 ful result being when the atropia was given before taking 

 the bean. 15 A, August 31, 1873, 276. 



COMPARATIVE POISONOUS QUALITIES OF METALS. 



In 1849 Rabuteau announced as a law that metals are 

 poisonous in proportion to the elevation of their atomic 

 weight, or the low degree of their specific heat. Thus, in 

 comparing cadmium and zinc, it was found that the former 

 was much more active than zinc, the two having the rela- 

 tions indicated. Barium, again, was more poisonous than 

 strontium, and the latter than calcium. This law has been 

 verified by comparison of the groups of tellurites. Thus tel- 

 lurites and selenites are extremely poisonous, much more so 

 than the sulphides, which are scarcely dangerous. Finally, 

 oxygen, which belongs to the group of sulphur, selenium, and 

 tellurium, according to Dumas, is only poisonous, as shown 

 by the recent researches of Bert, when animals are exposed 

 to the compressed gas, so that their blood shall be made to 

 contain about double the quantity which it has in the normal 

 condition. 6 B, February 10, 1873, 349. 



IXJURIOUS EMANATIONS FROM MANUFACTORIES. 



The necessity of legislative action for the protection of the 

 health of the community in the vicinity of certain manufact- 

 uring establishments is shown by the experience with the 

 Freibers: lead-smeltino- works. All ves^etation has been de- 

 stroyed in the vicinity, and a pine forest at a distance of four 

 miles has been considerably injured. Cattle feeding on the 

 fodder of the district experience peculiar attacks of sickness. 

 Analysis of the affected plants exhibits traces of arsenic and 

 lead, and an abnormal quantity of sulphuric acid. In view 

 of the variety of substances involved in the supposed agen- 

 cies, experiments were made to determine to which the result 

 was especially to be ascribed, and it was found that arsenic 

 was not at all injurious, successive fumigations of arsenious 

 vapor producing no efi*ect on the trees ; nor was vegetation 

 destroyed in the neighborhood of arsenic factories. When 



