ABSTRACTS 109 



A Study of the Effect of Spices on the Growth of Certain Organisms. 



Freda M. Bachmann. 



A study of the preservative effect of spices in foods was made in 

 order to determine the relative efficiency of the different spices in 

 inhibiting the growth of microorganisms. The molds used for inocu- 

 lation were the common ones found on spoiled fruits and vegetables, 

 species of Rhizopus, Penicillium, Aspergillus, and Alternaria. Of 

 the bacteria, B. coli, B. subtilis, and B. prodigiosus were studied. A 

 yeast isolated from Fleischman's compressed yeast was also used for 

 inoculation. The molds and yeasts were grown on Thaxter's potato 

 hard agar and the bacteria in the ordinary nutrient agar. 



A new method for obtaining a double plate was devised in which 

 the agar without the spice covers one-half of a petri dish and that 

 with spice the opposite half. In this way the organisms may be grown 

 on two kinds of media in one plate. The organisms were grown in such 

 double plates, also in spiced agar slants, and on steamed apples to 

 which varying amounts of spice were added. Besides the study of the 

 effect of ground spices, the alcoholic extracts, the active principles, 

 and the oils were used. 



Cinnamic aldehyde is most effective in preventing growth of all the 

 organisms studied. Eugenol and oil of allspice also have a considerable 

 preservative effect. Nutmeg is of little value as a preservative and 

 black pepper and ginger have practically no effect. It was found that 

 there is considerable variation in the sensitiveness of different organisms. 

 Molds were found to be more sensitive than the bacteria and yeast. 

 There is a very considerable difference in the amount of spice necessary 

 to prevent germination of mold spores and the amount necessary to 

 inhibit a growth of the mycelium. The results of this study for the 

 most part confirm those of Hoffman and Evans in their work on spices 

 as preservatives. 



SANITARY BACTERIOLOGY 

 Under Supervision of Henry Albert 



Influence of Conditions in the Barn Upon the Germ Content of Milk. 



M. J. Prucha and H. M. Weeter. 



The aim in this study was to measure the collective influence of the 

 barn conditions and operations on the bacterial contamination of milk. 

 Pails were steamed before each milking and the samples of milk for the 

 analysis were taken from individual cows when the pail of milk was 

 brought out from the barn into the adjacent milk room. 



The study was conducted from March to July in 1914 and 1915 in 

 three different barns. Barn I was very clean, barn II was not as clean 

 as barn I, and barn III was decidedly dirty. 1710 samples were taken 

 in all. The results are summarized in the following table: 



