red precipitate
Mercuric oxide (HgO) a heavy red crystalline powder formed by heating
mercuric nitrate, or by heating mercury in the air.
repousse
Ornamented with patterns in relief made by pressing or hammering on the
reverse side;
resorcinol (resorcin)
White crystalline compound, C6H4(OH)2, used to treat certain skin
diseases and in dyes, resin adhesives, and pharmaceuticals.
Rhamnus Purshiana (Cascara buckthorn )
Buckthorn of the Pacific coast of the United States, which yields
cascara sagrada.
rhatany
Dried root of South American shrubs (Krameria lappacea or K. argentea)
used as an astringent and in toothpaste and mouthwash.
rheumatic fever
Acute inflammatory disease occurring after an infection from group A
streptococci, marked by fever and joint pain. Associated with
polyarthritis, Sydenham's chorea, and endocarditis; frequently causes
scarring of the heart valves.
rheumatism
Painful disorder of the joints or muscles or connective tissues. Chronic
auto-immune disease with inflammation of the joints and marked
deformities.
rhus
Genus of vines and shrubs including poison ivy, poison oak, and poison
sumac.
rickets (rachitis)
Childhood disease caused by a lack of vitamin D or calcium and from
insufficient exposure to sunlight, characterized by defective bone
growth.
Rochelle salts
Potassium sodium tartrate; colorless efflorescent crystalline compound,
KNaC4H4O6.4H2O, used in making mirrors, in electronics, and as a
laxative