The dilute solution of acridine and its salts shows purple or green fluorescence. The dilute solution of salts has green fluorescence, and when diluted, it becomes free acridine due to the hydrolysis of brine, showing purple fluorescence. The aqueous solution is weakly alkaline. Chemicalbook reacts with inorganic acids to form salts. Acridine is very stable, its structure is similar to anthracene, and its chemical properties are also very similar. Both steam and solution are irritant, which strongly irritates skin and mucous membrane. Inhalation of steam may cause cough.