rush
  Stiff marsh plants of the genus Juncus, having pliant hollow or pithy
  stems and small flowers with scale-like perianths (outer envelope of a
  flower,).

sago
  Powdery starch from the trunks of sago palms; used in Asia as a food
  thickener and textile stiffener.

sal-ammoniac
  ammonium chloride; white crystalline volatile salt NH4Cl, used in dry
  cells and as an expectorant called.

saleratus
  Sodium or potassium bicarbonate used as a leavening agent; baking soda.

salicylate
  Salt or ester of salicylic acid.

salicylic acid
  White crystalline acid, C6H4(Oh)(COOH), used to make aspirin and to
  treat skin conditions such as eczema.

salol
  White crystalline powder, C13H10O3, derived from salicylic acid and used
  in plastics, suntan oils, analgesics and antipyretics.  Was a trademark.

saltpetre (potassium nitrate, saltpeter, niter, nitre)
  (KNO3) used especially as a fertilizer, explosive and a diuretic.

salt rheum
  Popular name in the United States, for skin eruptions, such as eczema. 
  Eczema; inflammatory skin disease, indicated by redness and itching,
  eruption of small vesicles, and discharge of a watery exudation, which
  often dries up, leaving the skin covered with crusts;—­called also
  tetter, and milk crust.

sanguinaria
  Rhizome (horizontal, underground stem) and roots of the bloodroot
  (Sanguinaria canadensis) used formerly as an expectorant and emetic.

sedulous
  Persevering and constant in effort or application; assiduous.

senna
  Plants of the genus Cassia, having showy, nearly regular, usually yellow
  flowers.  Dried leaves of Cassia angustifolia or C. acutifolia, used as a
  cathartic.

santonin
  Colorless crystalline compound, C15H18O3, wormwood, especially
  santonica; used to expel or destroy parasitic intestinal worms.

sarsaparilla
  Tropical American plants, genus Smilax, with fragrant roots used as a
  flavoring.  Dried roots of any of these plants.  Sweet soft drink flavored
  with these roots.

savin
  Evergreen Eurasian shrub (Juniperus sabina) with brownish-blue
  seed-bearing cones and young shoots that yield an oil formerly used
  medicinally.

scrofula (struma)
  A form of tuberculosis affecting the lymph nodes, especially of the
  neck.  Common in children.  Spread by unpasteurized milk from infected
  cows.

scurf
  Scaly or shredded dry skin, such as dandruff.

scurvy
  Disease caused by deficiency of vitamin C (citrus fruit; oranges,
  limes,..); causes spongy and bleeding gums, bleeding under the skin, and
  extreme weakness.