USE OF NITRIC ACID IN CONTROL OF pH AND NITRATE LEVELS IN NUTRIENT SOLUTION.

TRELEASE and TRELEASE (2) have called attention to the advantages, froln the standpoint of pH control, of using mixtures of aimmiiionliumii and nitrate salts in making up nutrient solutions. Sulphuric acid is customarily employed as a means of adjusting the pH of solutions during an experiiiient. The purpose of this paper is to call attention to the advantages of using nitric acid as a means of maintaining at one and the samiie time both H-ion concentrations and nitrate levels. The writer has used nitric acid for this purpose over a number of years with considerable success.