Renault P F, Schuster C R, Heinrich R, Freeman D X
Science. 1971 Nov 5;174(4009):589-91. doi: 10.1126/science.174.4009.589.
A spirometer was used to deliver marihuana and placebo smoke to human subjects. This procedure produced linear dose-effect curves on heart rate and replicable dose effects in individual subjects. No differences were observed between experienced and inexperienced smokers in responsiveness to heart rate increases produced by marihuana.
