Hairy cell leukemia (HCL) 1  Is a type of blood cancer that begins in the bone marrow. 2  Is a rare type of leukemia in adults.  Hairy cell leukemia gets its name from the short, thin projections that look like hair on its cells.
In 1799 Humphrey Davy discovered anesthetic properties of nitrous oxide (N20)---also known as laughing gas.. He had recently joined Thomas Beddoesâ Pneumatic Institution (established 1798) for treatment of disease by inhalation.
Not until 1889 was the protozoal (single celled parasite) cause of malaria discovered by Alphonse Laveran working in Algeria, and only in 1897 was the Anopheles mosquito demonstrated to be the vector for the disease by Ronald Ross.