There has never been an analysis of Cactus grandiflorus made and very little is known of its chemistry, nevertheless there are on the market certainly widely advertised proprietary, or semi-proprietary, preparations said to contain definite quantities of cactina or cactin, described as an alkaloid or, less definitely, as a concentration, on which the therapeutic activity of the several preparations depends. While cactin is said to be a concentration, the manufacturers of cardiac tonic (cactin) claim that each pillet contains 1/134 grain, a very unusual and minute dose, and explicable only on the assumption that its potency and constancy of composition are comparable to such alkaloids as strychnin and atropin.
Cactus grandiflorus (Linné), Cereus grandiflorus (Miller and De Candolle), is a member of a large family, and an understanding of the subject necessitates the consideration of other members of the cactus family, for there is probably a certain amount of confusion
HATCHER RA. CACTUS GRANDIFLORUS AXD CACTIN OR CACTINA.. JAMA. 1907;XLIX(12):1021-1025. doi:10.1001/jama.1907.25320120043002h