N.Y. General Business Law § 320: Standard of purity

§ 320. Standard of purity. The gas furnished or supplied by any

corporation, association, partnership or person in any city of the

second class shall be free from sulphuretted hydrogen, to be determined

by exposing for thirty seconds a slip of white paper saturated with

acetate of lead to a jet of gas flowing about five feet per hour, and

each one hundred cubic feet shall not contain more than ten grains of

ammonia nor twenty grains of sulphur.