The illustrations are by Larry Todd, the underground cartoonist who created the drug-addled Dr. Atomic, along with some pretty incredible fantasy and sci-fi art. Todd also illustrated Gottlieb’s The Book of Acid and Ancient and Modern Methods of Growing Extraordinary Marijuana, both from 1975.
Todd by himself wrote, illustrated, and self-published Dr. Atomic’s Marijuana Multiplier (1974)—complete with some very complicated chemical engineering instructions—which you can read in its entirety at Count Your Culture.