Size of colonies, 262 Slanted tube cultures, 223 Slides, to clean new, 22 used, 23 Smear culture, 224 description of, 268 Soap liquid, 346 Soda solution, storage of stock, 154 Sodium bicarbonate in milk, test for, 443 Soil, analysis of, qualitative, 476 quantitative, 473 collection of samples, 471 Solid media, 147 Soluble toxins, 144 Soyka's milk rice, 189 Spear-headed spatula, 402 Special media, 182 Specific serum, 379 dilution of, 382 Spherical aberration, 55 Spirillum, morphology of, 133 Spirochæta, morphology of, 133 Spirochætes in tissues, to stain, 124 Spleen extract, 149 Sporangium, 127 Spore formation, arthrogenous, 138 endogenous, 138 method of, 138, 273 germination, method of, 140, 274 observation of, 140, 273 Spores, characters of, 139 classification of, 139 double stain for, 106 to stain, 106 Stab culture, 224 description of, 265 Stage micrometer, 62 of microscope, 52 Staining methods, 90 paraffin sections, 121 reactions of bacteria, 274 Stains intra-vitam, 77 negative (Burri), 77 rack for, 72 Standard graduated pipettes, 7 soda solution, 154 Standardisation of media, 154 Standardising bouillon, 155 Staphylococci, morphology, 132 Staphylococcus in milk, 456 Steam steriliser, Arnold, 35 Koch, 35 to use, 35 streaming, 35 Sterigma, 127 Sterilisation by chemicals, 27 by dry heat, 28 by filters, 40 by moist heat, 32 by streaming steam, 35 by superheated steam, 36 of albuminous liquids, 32 of gases, 40 Sterilising agents, 26 Stichcultur, 224 Stock dilutions, 497 nutrient media, 163 plate for isolation work, 253 Storage of media in bulk, 159 of tubed media, 161 Store boxes for media, 161 Streak culture, 224 description of, 268 Streaming movement, 80 steam, 35 Streptobacilli, morphology, 133 Streptococci in soil, 477 in water, detection of, 432 morphology of, 132 Streptococcus pyogenes longus in milk, 455 Streptothrix, morphology of, 133 Strichcultur, 223 Structure, internal, of colonies, 265 Study of pathogenic bacteria, 408 Subcutaneous inoculation, 353 Subdural inoculation, 361 Substage condenser, 54 Sugar agar, 185 dextrose bouillon, 184 gelatine, 184 media, preparation of, 177 Sulphindigotate agar, 181 bouillon (Weyl), 181 gelatine (Weyl), 181 Sulphuretted hydrogen in cultures, test for, 290 Sunlight, action of, 309 Superheated steam, 36 Superior lethal coefficient, 310, 313 Suppuration, organisms of, 409 Surface characters of colonies, 264 plates, 230 Surgical motor, electric, 360 Swarm spores, 127 Syringe for subcutaneous inoculation of solid material, 354 hypodermic, 344 Tatin's operating table, 351 Taxonomy, 262 Teat-pipettes, 10 Temperature, action of, 299 optimum, 298 pressure table, 500 range, 298 taking, 340 Test objects for objectives, 57 Testing filters, 478