Determinations of ammonia in water supplies go back to the time of Chevreul in 1811. Titration procedures for the estimation of the substance were worked out by Boussingault (2), Bineau (1) and Thompson (9) during the 18SO\u27s. And there are already numerous modifications of the method for the estimation of total organic nitrogen developed by Johann Kjelclahl (6) in the Carlsberg Laboratory, in Copenhagen, in 1883. It is not meant to imply, by the title given this paper that basically new and original methods for the determination of nitrogen as ammonia or in its organic compounds are to be presented. Only modifications of the procedures and of the apparatus commonly employed in these determinations will be described. However these modifications have been found helpful in our laboratory work on specimens of sewage and of stream waters and it is believed that other persons who are required to analyze large numbers of such samples may also find the modifications advantageous
