826 THE AMERICAN JOURNAL OF SOCIOLOGY
impounded animals. The bodies are reduced to grease and fertilizer, as in Dresden.
Smoke prevention. Associated with street-cleaning in the work of keeping the air as clean and healthful as may be, is smoke prevention. Over forty industrial firms exhibited vari- ous fuels and appliances for the prevention or consumption of smoke. Complete combustion was the end in view, whether it was to be attained by good fuel or by proper stoking, or both. Mechanical stokers, automatic stokers ; various sorts of grates, arranged in steps, cooled by a system of water pipes, etc.; improved drafts, and many other appliances were to be seen in full-sized models, and some in operation. Two municipalities, Miinchen and Dresden, have smoke-inspection departments which presented small exhibits. The Dresden smoke inspector and his assistants are supplied with cards showing various pro- portions of black and white. The gray and gray-black patches on the cards are to be compared with smoke columns issuing from chimneys of factories and dwelling-houses, and when the smoke density is reported as excessive the offender is fined. Ignorance as to the proper manner of firing is recognized as, in large measure, responsible for the smoke nuisance; and conse- quently the department issues rules for firing. It must, however, be frankly admitted that such rules, helpful and necessary though they be, are at best only suggestive, for inspection of firing in private houses is impracticable. Nevertheless, there might be deduced from this the idea of municipal examination of firemen and stokers in large establishments, as to their knowledge of proper firing. The Dresden department requires, further, regu- lar monthly chimney-sweeping. It will be seen that the aim is to prevent as large a part of the smoke nuisance as possible, even though the absolute prevention of smoke is not yet possible.
Disinfection. This very important social function for limiting the field of infectious diseases is not yet fully municipalized. Berlin, Coin, Hamburg, and Bremen have full service. Several other cities have disinfecting establishments, as Dresden, Halle, Stettin, Frankfurt a. M., and Strassburg. For the disinfection of bedding, clothing, etc., the dry-heat process has been proved
