Classification.--Variation.--Where bacteria are found.

II.--MISCELLANEOUS USES OF BACTERIA IN THE ARTS.

Maceration industries.--Linen.--Jute.--Hemp.--Sponges.--Leather.
--Fermentative industries.--Vinegar--Lactic acid.--Butyric acid.--
Bacteria in tobacco curing.--Troublesome fermentations.

III.--BACTERIA IN THE DAIRY.

Sources of bacteria in milk.--Effect of bacteria on milk.--
Bacteria used in butter making.--Bacteria in cheese making.

IV.--BACTERIA IN NATURAL PROCESSES.

Bacteria as scavengers.--Bacteria as agents in Nature's food
cycle.--Relation of bacteria to agriculture.--Sprouting of seeds.
--The silo.--The fertility of the soil.--Bacteria as sources of
trouble to the farmer.--Coal formation.

V.--PARASITIC BACTERIA AND THEIR RELATION TO DISEASE

Method of producing disease.--Pathogenic germs not strictly
parasitic.--Pathogenic germs that are true parasites.--What
diseases are due to bacteria.--Variability of pathogenic powers.--
Susceptibility of the individual.--Recovery from bacteriological
diseases.--Diseases caused by organisms other than bacteria.

VI.--METHODS OF COMBATING PARASITIC BACTERIA