FOODS HUMAN NUTRITION. 373 



ing nucleoproteid is found with 2.32 to 2.68 pei* cent pliosphoi'us. The amount 

 of iron removable by cooking in water varies, being Iiigbest in the first broth, 

 which shows from 1.48 to 2 per cent. The filtrate from the nucleoproteid con 

 tains from 20 to 2.5 per cent of the total amount removable in hot water. 



Some observations on the study of the intestinal bacteria, A. I. Kendall 

 {./our. Biol. Cliciii.. 6 ( tOO!)). Xo. 6'. />/*. .',99-007). — The author states that his 

 purpose in this paper is to show in a general way the procedure and the use 

 of media through which a more comprehensive idea of the significance of 

 bacterial activity in the Intestine may be obtained. In the data discussed he 

 considers the subject from the standpoint of the interdependence of diet, bac- 

 teria, and the end products of bacterial activity which appear in the urine, and 

 the methods of procedure outlined are based upon such relations. 



"The nature of the diet practically determines the dominant types of intesti- 

 nal bacteria, and these organisms in turn, acting upon the digestive products 

 of the diet elaborate the end products of their activity which apijear in the 

 urine. 



"With the exception of a few anaerobes (which derive their oxygen from 

 the combustion of carbohydrates) the majority of the prominent types of the 

 normal flora which develop on a protein diet grow luxuriantly in media free 

 from carbohydrate, while those developing on a carbohydrate regimen grow 

 poorly, or even not at ail. unless carbohydrate is jjresent. Hence by inoculating 

 portions of the mixed fecal flora with gelatin and milk and observing the degi-ee 

 and rapidity of peptonization, it is possible to form a judgment of the character 

 of the lu-oteolytic flora. At the same time these media furnish conditions so 

 favorable for the growth of these organisms that they can be regarded as 

 selective for the isolation of the proteolytic flora. 



" On the other hand, through the use of media containing carbohydrate, and 

 particularly the acid dextrose broth, one obtains a fairly specific enrichment of 

 the acidophilic flora, characteristic of a carbohydrate regimen. 



" Furthermore, through the use of these selective media it is possible to 

 form a judgment of the completeness of the bacterial response to the nature of 

 the diet. For example, if the experimental animal is on a carbohydrate regimen, 

 the pi-esence or absence of growth in protein media will indicate the presence 

 or absence of proteolytic bacteria, since the acidophilic organisms do not grow 

 well in these media and can not, therefore, inhibit the growth of these organ- 

 isms. Conversely, with a protein diet, the presence or absence of acidophiles 

 may be determined by inoculating the mixed fecal flora into acid dextrose broth, 

 which is unfavorable for the development of the proteolytic types. These deter- 

 minations may be made roughly quantitative for the different types by inocu- 

 lating definite amounts of the mixed fecal flora into appropriate media. 



" The end products of bacterial activity which appear in the urine are 

 important for two reasons : They indicate the types of bacterial activity in the 

 intestinal tract, and their reproduction in artifical media by pure cultures 

 derived from the intestinal flora furnishes strong presumptive evidence of the 

 jiarticipation of these organisms in the process." 



The fecal bacteria of healthy men, W. J. MacNeal. L. L. Latzer and J. E. 

 Kerr (Jour. Infect. Diseases, 6 (1909). No. 2, pp. 123-169, fig. i).— Experi- 

 mental methods are outlined and the results reported of an extended study of 

 feces, undertaken at the department of animal husbandry. University of Illinois, 

 in connection with an experiment on the influence of cured meats upon human 

 health. 



" During the course of the work 266 stools were examined. About three- 

 fourths of these serve as the basis of this paper." 



