Quaternary amines, =152=. Quercetin, 84, 118. Quercitrin, =84=. Quinine, 155, =157=. Quinoline, 155, 158. Radiant energy, 19. Raffinose, 45, 52, =53=. Rape-seed oil, 130. Reducing sugars, 39, 49. Reductases, 186, 190. Reserve food, 21. Resenes, 149. Resins, 18, 146, =149=. Resorcinol, 95. Respiration, 18, 121, 235, 236. Rhamnase, =77=, 189. Rhamnetin, 84. Rhamnose, 35, 52, 77, 79. Rhodeose, 35, 81. Rhodophyllin, 107. Ribose, 35. Ricin, 176. Rubiadin, 83. Rubiphyllin, 107. Saccharide, =31=. Salicin, =80=. Saligenin, 80. Salinigrin, =81=. Salts, 224, =227=, 237. Sambunigrin, 87. Sapogenins, 90. Saponification, 134. Saponification value, 138. Saponins, =90=. Sapotoxins, 90. Saprophytes, 16. "Saturated" acids, 132. Scopolin, =82=. Secalin, =63=. Secondary amines, 152. Secretions, 20. Sedoheptose, =36=. Semipermeable membranes, =228=. Sensitizers, 27. Serine, 168. Silicates, 12. Silicon, 4, =12=. Silver, 247. Simple proteins, 165, 174, =175=. Sinalbin, 89. Sinalbin mustard oil, 89. Sinapin acid sulfate, 89. Sinigrin, =88=. Sinistrin, =62=. Sitosterol, 136. Skimmetin, =81=, 82. Skimmin, =81=. Soaps, 134, 208. Sodium, 4, 9, =12=, 13, 14. Sodium stearate, 133. Sol, 205. "Soluble starch," 60. Sorbitol, 48. Sorbose, 36, 38, 45, =48=. Specific rotatory power, =38=, 39. , of fructose, 39, 47. , of galactose, 49. , of glucose, 39, 47. , of maltose, 51. , of raffinose, 53. , of sucrose, 39. Spermaceti, 129, 133. Stachydrine, 155. Stachyose, 54. Starch, 8, 22, 28, 30, 31, 45, =59=, 64. "Starch paste," 60. Stearin, 131, 134. Stereo-isomerism, =32=. Stigmasterol, 136. Structural adaptations, =255=. Structural isomerism, =32=. Strychnine, 155, =157=. Substrate, 186. Sucrase (_see_ invertase). Sucrose, 28, =49=, 64. Sugars, 8, 18, 22, 28, 30, 31. Sulfur, 3, 5, =11=, 148. Sulfuretted oils, 147, =148=. Sulfur test, 174. Sunflower-seed oil, 130. Surface boundary phenomena, =231=. Surface energy, 231. Surface tension, 231. "Survival of the fittest," 254. Suspensoids, 206, 214. Suspensions, 206. Synergic foods, 2, 20. Synthesis, 18.