THE ATMOSPHERE. 



45. Is the action of the atmosphere upon combustion, 

 a chemical or mechanical process ? 



46. Is the oxidation of metals a chemical or mechani- 

 cal operation ? 



47. Is the weight of the atmosphere a chemical or me- 

 chanical property ? 



48. In how many divisions may all the properties and 

 operations of the atmosphere be classed 1 



49. Is the elasticity of air a chemical or mechanical 

 property ? 



50. What is the principal agent in the process of 

 bleaching ? 



51. What acid is composed of three parts of oxigen, 

 and one of nitrogen, nitric, or sulphuric ? 



52. If sulphur be burned in oxigen gas, what acid is 

 the result, sulphuric, or muriatic ? 



53. How is phosphoric acid formed ? 



54. What part of the vegetable kingdom is oxigen 1 



55. Of what minerals does oxigen constitute a part ? 



56. Is any substance more universally diffused through 

 the -material creation than oxigen, and what ? 



THIS pamphlet is the first number of a series of ' tracts,' 

 designed as instruments for operating in the great and 

 common cause of Popular Education. They are in- 

 tended to be brought within the comprehension, and to 

 meet the wants of the great mass of the community ; 

 especially of the industrious classes, who have neither 

 timo nor opportunities to devote their lives to intellectual 

 pursuits. It is hoped they will prove to be worthy and 

 agreeable companions in every family circle, and that they 

 will take some part in their conversation, and if so, that 

 they will enliven, extend, and ennoble, this seat and 

 source of individual and national character and happi- 

 ness. 



Endeavors will be made to render these sheets welcome 

 visitors to schools, by carrying to them useful and enter- 

 taining knowledge, and in a measure to relieve those 



