In analytical practice for the students, a method for the systematic separation of cations has been proposed using non-sulfide as the group reagents. This procedure was named the alkaline method, and was designed with the caution so as not to contaminate the environment, employing only the usual laboratory reagents and apparatus. Except for the six poisonous metals such as As, Cd, Hg, Bi, Sb, and Cr, seventeen kinds of common cations were divided into five groups by hydrochloric acid, ammonium hydroxide, sodium sulfite, and sodium hydroxide, and were detected succeedingly
