106 Bacteria in Relation to Country Life 



pal and state authorities to pass regulations for the 

 treatment and purification of sewage previous to its 

 discharge into rivers or lakes. 



The early legislation oil sewage-purification was 

 antecedent to the development of modern bacteriology. 

 The Rivers -Pollution Act, which made it compulsory 

 for some communities to take steps toward the purifi- 

 cation of their sewage, was passed in England in 1865. 

 It was but natural at that time to seek in chemical 

 methods a means for the proper purification of sewage, 

 and we find, accordingly, a number of such methods 

 suggested, or actually employed for the purpose. A 

 patent for the chemical purification of sewage by the 

 lime process had been taken out in 1846 by Higgs. 

 Other patents were taken out by Wickstead in 1851 and 

 in 1854, and a company was organized at Leicester for 

 the manufacture of fertilizer out of sewage. In 1852 a 

 patent was taken out for the treatment of sewage by 

 means of alumina and charcoal. Similar patents were 

 granted in the period from 1853 to 1860. All of these 

 processes are based on the more or less thorough re- 

 moval of the organic matter in the sewage, thus making 

 it non-putrescible. The salts of alumina or of iron react 

 with the substances present in the sewage and form 

 flocculent masses, which gradually settle out to the 

 bottom, dragging down the bacteria entangled in them. 



The chemical methods of sewage-purification proved 

 satisfactory up to a certain point. They freed the 

 sewage from the suspended matter and reduced the 

 number of bacteria in this way, producing effluents in 

 gome cases, which did not putrefy as readily as the 



