September 10, 1915] 



SCIENCE 



353 



of Moro. During continued milk or lactose 

 feeding the acidophilus type may give way even- 

 tually to B. hifidus. Similar results were obtained 

 in the domestic fowl, the acidophilus hacillus being 

 the most prominent. The feeding of other carbo- 

 hydrates, dextrose, maltose, levulose, dextrin and 

 starch did not bring about such a change. 



The feeding of bacteria, even in large numbers, 

 will in itself exert very little if any influence on 

 the intestinal flora. B. iulgaricus suspensions ob- 

 tained from plain agar growths could be recovered 

 only occasionally from the feces, and then in very 

 email numbers only. On the other hand, when 

 sterile milk, whether sweet or sour, was fed to 

 white rats which exhibited the usual mixed flora in 

 which organisms of the acidophilus type were very 

 few or absent, B. acidophilus, which in many re- 

 spects is practically indistinguishable from B. 

 iulgarieus, rapidly made its appearance in the in- 

 testine and for a time occurred there in relatively 

 large numbers. 

 A Simple Test for B. sporogenes in Milk and 



Water: John Weinzikl. 



The sample of milk to be tested is placed in a 

 sterile test tube, and enough solid paraffin is added 

 to make when melted, a layer one eighth of an inch 

 in thickness. The tubes are then placed in the 

 Arnold and heated at 80° C. for ten minutes. 

 After heating, they are cooled rapidly; this causes 

 the melted paraffin to solidify and form a cover 

 which effectively excludes atmospheric oxygen. 

 The cultures are then incubated at 37° C. for 24 

 hours. If B. sporogenes is present, it digests the 

 lactose and forms gas which lifts the paraffin plug. 



The test is simple, cheap and easy of applica- 

 tion. When applied to market milk it gave the 

 following results: 



90 samples of 5 c.c. milk each gave 28 per cent, 

 positive. 



112 samples of 10 c.c. milk each gave 37.5 per 

 cent, positive. 



34 samples of 15 c.c. milk each gave 50 per cent. 

 positive. 

 Vtensils as a Source of Bacterial Contamination 



of Milk: M. J. Peucha, H. A. Harding, H. M. 



Weeter. 



This investigation attempted to measure the 

 amount of bacterial contamination received by the 

 milk from the utensils in which it was handled be- 

 tween the cow and the milk bottle. 



The utensils were carefully washed in the ordi- 

 nary way, being scrubbed with brush in a warm 

 solution of Wyandotte and then rinsed out with 

 warm water. 



In the accompanying table is given the summary 

 of the experiments. 



All Utensils Sterile 



Bacteria 

 per C.c. 



1. Milk leaving the barn 2,558 



2. Bottled mUk 3,875 



Utensils Washed — Only Bottles Sterile 



3. Increase due to pails 57,077 



4. Increase up to clarifier 15,353 



5. Increase due to clarifier 172,763 



6. Increase due to cooler 19,841 



7. Increase due to bottler 247,611 



8. Total in bottled milk 515,203 



An Improvement in the Composition of Lactose 



Bile: Thomas W. Melia. 



Lactose bile, as employed at present, has certaia 

 disadvantages. 



First: The bile is not always fresh. 



Second: The media, after sterilization, contains 

 a heavy sediment in the fermentation tubes which 

 interferes with the development of the test. 



Third: Many authors have criticized the inhibit- 

 ing power of the bile salts upon B. coli. 



In regard to the first disadvantage it was found 

 best to purchase ox gall from freshly slaughtered 

 animals and have it delivered within a few hours 

 to the laboratory. It is then evaporated to dryness 

 in a vacuum dryer and stored away in one pound 

 airtight containers. The bile will keep indefinitely. 



The sediment present in fresh bile and in the 

 sterilized media was found to contain mucin, lime 

 salts and broken gall stones (eholesterine) prob- 

 ably formed by the streptococcus growth. The bile 

 should be settled and only the clear supernatant 

 liquid used. 



The sediment in the fermentation tubes may be 

 prevented by making a five per cent, instead of a 

 ten per cent, solution of bile media. 



The known inhibiting power of bile salts led to 

 an investigation of the best strength of bile media 

 to employ. 



Table showing relative efficiency of the five and 

 ten per cent, bile media on ordinary quality of 

 drinking waters (60 in number) 



