Arsphenamine. Regulations for control of manufacture, importation, and sale of arsphenamine and its derivatives, neoarsphenamine, sodium arsphenamine, silver arsphenamine, neosilverarsphenamine, phospharsphenamine, and sulpharsphenamine, referred to collectively as arsphenamines, supplementary to Regulations for sale of viruses, serums, toxins, and analogous products, approved Aug. 1, 1923.