PELLAGRA: CAUSATION AND A METHOD OF PREVENTION

1916 Journal of the American Medical Association  
quite as great in the case of rapid filters as with those of the slow sand type. The safety of the mechanical filter effluent is no more certain or absolute than that of slow sand filters.
doi:10.1001/jama.1916.02580330005002 fatcat:rk6vtomj2ffnfnnaygbckar6cm