Through the courtesy of the Dupont Powder Company Dr. George E. Ebright, of San Francisco, was enabled to examine and question about twenty men employed in the manufacture of nitro-glycerine. Here is the result, in his own words, which goes to make up a very compact proving of this drug:

      “A throbbing headache is characteristic. It frequently begins in the forehead and moves to the occipital region, where it remains for from an hour or two to three or four days. It may be associated with a sense of exhilaration at first, but most of the patients are depressed Restlessness and inability to lie quietly in bed are often present. Many patients cannot sleep. So that the unfortunate victim is doomed to make the best of his pain propped up in bed through a couple of sleepless, restless nights, often with nausea or vomiting, and in severe instances with diarrhoea. Maniacal attacks were not called to my attention by the men I examined.”

      “Concerning permanent effects, the general health of the men working in nitroglycerin appeared to be in no way impaired; on the other hand, they were in remarkably good condition. Several factors bore on this result. In the first place, they were selected men chosen for reliability and sobriety, and a bonus system was in vogue for continued good service. On account of the hazard of their occupation, smoking tobacco was not used With the exception of one case of chronic valvulitis of rheumatic origin, the examination of their hearts showed no abnormalities. The examination of the radial arteries showed no abnormal changes. Blood-pressure ranged within normal limits. There was no evidence of chronic low blood-pressure, and no appreciable relaxation of the arteries or of the capillaries, I found no instances of shortness of breath, nor did Dr. Fernandez, who has charge of the health of the men, notice that it ever occurred. As far as the complexion of the men was concerned, there were no evidence of destructive blood changes, such as might have been anticipated by constant destruction of oxyhemoglobin. The amount in the system at any one time was too small.”

      “Examination of the urine of nine men revealed no glycosuria. This included one man suffering from nitro-glycerine headache. In his case there was no flushing of the skin or relaxation of the radial artery, although he was experiencing throbbing pain in the head and dizziness and nausea. His systolic blood-pressure was 122 mm. Hg.”

      “Alcohol enhances the toxic symptoms by relaxing the blood vessels. This is true to the degree that a man who has been exposed to nitro-glycerin all day without ill effects may precipitate a severe headache in a very few minutes by taking a cocktail.”