Sentence:  Visited in company with the agent of the Opium farmer 4 Opium shops, found them filled with Chinese except one which had in addition 7 Malays and natives of India. Amongst these were 3 tailors; one woman 30 years old, was there smoking her pipe,—she had been in the habit of doing so for 3 years at the rate of 3 <WSD>hoons</WSD> daily,—before she commenced the habit of smoking had children but none since,—thinks that it is owing to the bad habit,—would like much to give up but is frightened. 
Meaning of the word marked with <WSD> tags:  A unit of weight (about 0.378125 of a gram, or 0.0133 of an ounce) used to measure opium in British-controlled parts of Asia; a candareen.