That it is not only the right but also the duty of the physician to know the composition of what he prescribes for his patients is so generally admitted that few have attempted to market preparations of avowedly secret composition. When the Council first began its work, it was common to see chemical formulas or statements of composition published which a chemist or a pharmacist was able to pronounce at a glance as impossible.[6] It was not unusual to find that the promoter published “a formula” for his preparation, rather than “the formula.”[7] Today, however, a more prudent, if not more honest, course is pursued. This gives a “formula” which is correct so far as it goes, but which fails to divulge the actual composition of a preparation. When it is considered that many physicians are not any too conversant with the chemistry and pharmacy of drugs, it is not surprising that some administered the proprietary “Venarsen,” regarding the composition of which they had only the vague statement that it was “... a comparatively nontoxic organic arsenic compound, 0.6 gm. representing 247 mg. (3-3/4 grains) of metallic arsenic in chemical combination ...” in the belief that a preparation similar to that first introduced as salvarsan was being used. That “Venarsen” contained its arsenic as sodium cacodylate--a notoriously inactive state of combination--does not justify the intravenous administration of a drug of unknown composition. [6] Puckner, W. A.: The Abuse of Chemical Formulas, Reports A. M. A. Chemical Laboratory =3=:7, 1910. [7] The Formula for Glyco-Thymoline, J. A. M. A. =52=:147 (Jan. 9) 1909. While for the present it probably is not feasible to require, on the part of those who manufacture medicinal preparations, such professional training as is required of those who prescribe and those who dispense them, it certainly is not too much to require, as does Rule 2, that a manufacturer shall be able to demonstrate that his preparation has the composition claimed for it. Nor is it sufficient for him to know that the ingredients claimed as constituents were used in the manufacture. The fallacy of his method of reasoning was furnished by the physician who reported that he had personally added the required amount of mercuric iodid for a batch of “Mercol” which, nevertheless, was devoid of mercury.[8] Acceptance of this rule by manufacturers will permit physicians to have a more accurate knowledge of the composition of preparations such as “Taka-Diastase”[9] and “Iodeol”.[10] [8] Hunt, Reid, and Seidell, Atherton: Howell’s Mercol, J. A. M. A. =52=:225 (Jan. 16) 1909. Howell’s Mercol Again: Another Analysis Fails to Reveal the Presence of Mercury, J. A. M. A. =52=:1595 (May 15) 1909. [9] Taka-Diastase and Liquid Taka-Diastase: Report of the Council on Pharmacy and Chemistry, J. A. M. A. =59=:50 (July 6) 1912. [10] Iodeol and Iodagol: Report of the Council on Pharmacy and Chemistry, J. A. M. A. =69=:1725 (Nov. 17) 1917.