220 The Atmosphere in relation to Malaria, 



if the quantity of this gas were appreciated, the great step 

 would be gained. For this purpose, in 1830, he passed a 

 given weight of impure marshy air through a red hot glass 

 tube, and collected the water formed in a tube filled with 

 chloride of calcium. A quantity of air weighing from 

 4697 grs. to 4774 grs. in different trials, afforded -77 gr. 

 water, which is equivalent to '077 gr. hydrogen. When 

 the air, previous to being passed through the hot tube, was 

 brought in contact with sulphuric acid, it yielded no organic 

 matter. Hence, he concludes, that it is very probable, 

 that the malaria is a flocky matter, and that the employ- 

 ment of a veil as a precaution against the influence of 

 malaria may be efficacious. 



The preceding experiments, did not apparently indicate 

 the presence of hydrogen, when it had been previously 

 washed with sulphuric acid. To determine this precisely, 

 it was necessary to experiment with great nicety. A vessel 

 with sulphuric acid was made to communicate on one side, 

 with a gasometer filled with common air, and on the other 

 led into a tube 8 or 10 feet long, filled with chloride of 

 calcium. To the latter, was joined a glass tube filled with 

 asbestus, moistened by sulphuric acid ; a tube filled with 

 copper turnings and passing through a furnace followed 

 next, and conducted the air into another tube filled with 

 asbestus, soaked in sulphuric acid. In the last tube the 

 water was condensed, when any hydrogen was contained in 

 the air submitted to experiment. 



From 1609-6 grs. were obtained water= '01 72 gr. hydrogen 

 „ 5482-4 „ „ =-0443 



„ 6498-8 „ „ =-0477 



The proportion of hydrogen formed in the air on different 

 days is represented in the following table : 



Hydrogen in one part of Air. 



Weight. Volume. 



2nd and 3rd April, 1834, 0*000008 000013 

 4th and 5th „ 0*000007 0*00012 



23rd „ 0-000002 0-00004 



28th „ 0-000005 0*00008 



31st May, 0-000003 0*00005 



Boussingault, having thus, as he conceives established the 



