1 Calories Burned For Walking: 4.6 km/h (13 minutes per km). 2  Calories Burned For Walking: 4 km/h (15 minutes per km). 3  Calories Burned For Walking: 3.15 km/h (19 minutes per km).
The first true hypodermic syringe was created by Alexander Wood in 1853. He modified a regular syringe, which at that time was used for treating birthmarks, by adding a needle. He then used this new device for introducing morphine into the skin of patients who suffered from sleeping disorders.
During WWII, Nylon was used as a substitute for silk in parachutes. The first commercial use of this revolutionary petroleum product was for toothbrushes. On February 24, 1938, the Weco Products Company of Chicago, Illinois, began selling its new âDr. Westâs Miracle-Tuftâ â the earliest toothbrush to use synthetic DuPont nylon bristles. Americans will soon brush their teeth with nylon â instead of hog bristles, declared an article in the New York Times.