XI. Organisms in Water 218 XII. Spices 252 FOOD ADULTERATION. INTRODUCTION. Of the various branches cognate to chemical research which excite public attention, that of food adulteration doubtless possesses the greatest interest. To the dealer in alimentary substances, the significance of their sophistication is frequently merely one of profit or loss, and even this comparatively unimportant consideration does not always attach. But to the general community, the subject appeals to interests more vital than a desire to avoid pecuniary damage, and involving, as it necessarily does, the question of health, it has engendered a feeling of uneasiness, accompanied by an earnest desire for trustworthy information and data. The most usual excuses advanced by dishonest traders, when a case of adulteration has been successfully brought home to them--guilty knowledge being also established--are, that they are compelled to resort to the misdeed by the public demand for cheap commodities, that the addition is harmless, or actually constitutes an improvement, as is asserted to be the case when chicory is added to coffee, or that it serves as a preservative, as was formerly alleged to be the fact when vinegar was fortified with sulphuric acid. Pretexts of this sort are almost invariably fallacious. The claim that manufacturers are often forced into adulteration by the necessities of unfair trade competition possesses more weight--an honest dealer cannot as a rule successfully compete with a dishonest one--and has undoubtedly influenced many of the better class to co-operate in attempts to prevent the practice. The general feeling of uncertainty which exists in the public mind concerning the actual extent and importance of food adulteration is probably to be ascribed to two causes. In the first place, most of the literature generally accessible relating to the subject has been limited to sensational newspaper articles, reciting some startling instance of food-poisoning, often unauthenticated and bearing upon its face evidences of exaggeration. By reason of such publications, periodical panics have been created in our large cities which, however, as a rule quickly subside, and the community relapses into the customary feeling of doubtful security, until aroused from its apathy by the next _exposé_. The fact that the only reliable results of food investigation have, until recently, been confined to purely scientific journals, and therefore not prominently brought to public notice, is another explanation of the lack of creditable information which generally prevails concerning this species of sophistication.