.656 ANNUAL REPORTS OF THE DEPARTMENT OF AGRICULTURE. 



Slack ftll. — For the purpose of competition (here has spriinf;^ up 

 anion<; certain canners the practice of filling their cans partially 

 with food and adding a suflicient amount of water to fill to the re- 

 quired content. The water has been added especially to products 

 where its addition Avas not apparent to the observer, as in canned 

 tomatoes, and to other foods where its addition was apparent, but 

 wdiere the average corLsumer would not recognize it as added water, as 

 in cove oysters, in which only 1^ ounces of oysters were sometimes 

 placed in a can Avhich would hold nearly G ounces and the can then 

 filled with a weak brine. While these practices were not general in the 

 canning industry they were sufficiently prevalent to be regarded seri- 

 ously, and a study was made of the problem, including necessarily a 

 considerable amount of analytical work. The study was conducted 

 in a number of commercial canneries as well as in the laboratory, and 

 as a result food inspection decision 144 was issued, requiring cans 

 to be as full as practicable of the food supposed to be present and 

 forbidding the addition of unnecessary water. 



Tin contekt. — The study of the corrosive action of various canned 

 foods upon the tin of the receptacles and the consequent tin content 

 of the food preserved has been continued. About 30 varieties of 

 food in tin receptacles have been reexamined after an interval of 

 one year and the increased solvent action noted. The results are of 

 value in determining the character of container which should be 

 employed with the different varieties of food. 



The division has also collaborated with the research committee of 

 the National Canners' Association in a much more exhaustive investi- 

 gation of the same general nature. This work involved the deter- 

 mination of tin in about 250 samples of canned food, with the result 

 that the corrosive action of the foods on the container seems to be 

 due not only to the chemical action of the acids of the strongly acid 

 foods and of the volatile alkalies of some of the nonacid foods on the 

 uncoated plate, but also to the amount of oxygen included in the 

 can. A study of the action on tin plate of some of the nonacid 

 foods reported a year ago has been extended and Circular 79 has 

 been published, giving the results of the work. Food inspection 

 decisions 142 and 148, issued by the Board of Food and Drug Inspec- 

 tion, forbidding the use of saccharin and copper sulphate in food 

 products, will probably affect some canning methods. 



Sanitary Condition of Food Manufacturing Establishments. 



One of the most important problems in connection with the manu- 

 facture of food is the bettering of the sanitaiy conditions under which 

 t^he processes of manufacture are conducted. Several States have 

 enacted laws regulating the maintenance of food-manufacturing 

 establishments in a sanitary manner. This is not required directly 

 by the food and drugs act, but the question is important to its enforce- 

 ment, since the use of insanitary establishments sometimes results 

 in the production of foods which are regarded as in violation of the 

 Federal food and drugs act because of their content of filthy, decom- 

 posed, or putrid material. The question of sanitary conditions of a 

 factory, therefore, is inseparably connected with the question of spoil- 

 age in food. 



