By the turn of the last century, pharmaceutical giant Parke, Davis & Co. had fully embraced cannabis as a medicine. The company’s 1901 edition of Physician’s Manual of Therapeutics contains over 400 references to cannabis, recommending it as a primary treatment for a wide range of conditions including migraines, inflammation, neuralgia and epilepsy. However, company buyers faced a serious supply problem; as outlined in their Standardized Products catalogue from 1911,

“The imported Cannabis varies extremely in its activity and much of it is practically inert or flagrantly adulterated; so that the greatest watchfulness is necessary to insure getting a drug of good quality.”

The Quest for Standardization

Determined to obtain a consistent, potent supply, the company embarked on a mission to grow their own cannabis, Cannabis Americana, while at the same time standardizing their cannabis preparations through animal testing.

According to the company’s Therapeutic Notes newsletter (December 1898),

“We are prepared to carry the banner of standardization into this new field. We have established a very fully equipped physiological laboratory for the special purpose of testing drugs such as ergot, digitalis, strophanthus, cannabis indica, etc., whose therapeutic activities are neither fully nor satisfactorily determined by anything short of test upon the living organism.”

30,000 Pounds of Cannabis Rejected

The company settled on dogs, typically small ones around 25 pounds, as their test subjects. Company researchers E.M. Houghton, and Dr. Herbert C. Hamilton described the effects they were looking for in a 1908 American Journal of Pharmacy article:

“The stage of incoordination invariably follows in one to two hours: the dog loses control of its legs and of the muscles supporting its head, so that when nothing occurs to attract its attention its head will droop, its body sway, and when severely affected, the animal will stagger and fall, the intoxication being peculiarly suggestive and striking.”

Such “living organism” testing revealed that much of what importers brought them was bunk. A Parke-Davis ad from 1898 hints at the scale of the problem:

“Cannabis Indica, if therapeutically active, is manifested in the staggering gait, loss of muscular control, reduction of temperature, etc., followed by insensibility. If otherwise, the crude material is rejected as being inert, and within the past twelve months we have rejected over 30,000 pounds of Cannabis Indica. Parke, Davis & Co. is the only House engaged in this work.”

No Fatalities, Not Dangerous

Company researchers sometimes couldn’t resist providing massive doses of cannabis to the dogs. However, while overdoses often brought on unpleasant side effects, the subjects always fully recovered and the team was surprised to find they couldn’t induce a single death despite their best efforts. Houghton and Hamilton’s article noted that this was entirely consistent with the scientific literature of the day, which was devoid of reports of cannabis fatalities:

“At the beginning of our observations careful search of the literature on the subject was made to determine the toxicity of the hemp. Not a single case of fatal poisoning have we been able to find reported, although often alarming symptoms may occur. A dog weighing 25 pounds received an injection of two ounces of an active U.S.P. fluid extract in the jugular vein with the expectation that it would certainly be sufficient to produce death. To our surprise the animal, after being unconscious for about a day and a half, recovered completely. Another dog received about 7 grammes of solid extract cannabis, with the same result. We have never been able to give an animal a sufficient quantity of a U.S.P. or other preparation of the cannabis (Indica or Americana) to produce death.”

In 1917, after two decades of testing, Hamilton published another paper in American Journal of Pharmacy and concluded that cannabis, “while intoxicating in a sense, is not known to be fatal in a relatively immense dose and consequently is not a dangerous drug.”