542 



SCIENCE 



[N. S. Vol. XXXIII. No. 849 



The Normal Number of Body Cells in Cow's 

 Milk: E. S. Bkeed and I. Kead Stedger. 

 A report on some determinations made at Alle- 

 gheny College and the University of Gottingen by 

 the use of the direct method of counting these 

 cells devised by Prescott and Breed.' A series 

 of examinations was made of cream and skim 

 milks obtained in a variety of ways to deter- 

 mine what became of these cells when the milk 

 was separated or centrifuged. The results ob- 

 tained were so variable that the final conclusion 

 was that none of the methods using the centrifuge 

 can be made satisfactory enough to give results of 

 any value so far as determining the number of 

 cells present is concerned. A necessary corollary 

 of this conclusion is that all the deductions based 

 on the use of these methods, careful and pains- 

 taking as much of this work has been, are worth- 

 less so far as they are based on the nimierieal 

 factor alone. A daily examination of the milk of 

 three normal cows extending over a period of six 

 weeks indicates that there may be a cyclic varia- 

 tion in the number of these cells and showed 

 variations in numbers ranging from to 20,000,- 

 000 and more in milk which was apparently nor- 

 mal in every particular. 



What is the Value of Quantitative Bacteriological 



Determinations in the Control of City Milk 



Supply: H. A. Harding. 



Their educational value is slight because dairy- 

 men are unable to translate quantitative results 

 into terms of dairy processes and laboratory work- 

 ers are also unable to do this until they have lo- 

 cated the particular difficulty by other means. 



As legal standards quantitative results have 

 little value because they fluctuate so widely, de- 

 pendent upon the technique used. A variation of 

 100 per cent, is frequently observed between the 

 results of two equally accepted methods of de- 

 termination. 



They are not necessary, since the best results in 

 improvement of city milk supply can be obtained 

 without the aid of quantitative determinations. 



They are useful as a cheek upon the work of 

 dairy inspectors and in determining which dairies 

 are most in need of close observation. Where the 

 force of mspeetors is not adequate to a close 

 supervision of all the dairies, bacteriological deter- 

 minations will indicate where the inspector 's en- 

 ergy can be most wisely employed. 



Their greatest value is in measuring the sources 

 of infection. There is at present a lack of much 



data and thousands of dollars are being wasted in 

 present attempts at producing sanitary milk be- 

 cause the relative importance of various avenues 

 of infection are not understood. 



Apparatus for Collection of Deep-water Samples: 



Patn B. Parsons. 



Description of a sampling apparatus for use in 

 collecting samples of water for bacteriological 

 examination, where the depth of water is very 

 great and the currents are strong. 



A single rope used for lowering and raising the 

 lead pipe container and for breaking off the neck 

 of the vacuum tube or releasing the stopper. 



Also a description of an apparatus for the col- 

 lection of chemical samples and one especially 

 adapted for dissolved oxygen samples, where the 

 samples must be taken in very deep water and the 

 line kept plumb in the currents. 



Bacteria in the Waters of New York Harbor: 



Payn B. Parsons. 



Table giving the average number of bacteria 

 in the water of New York harbor at the surface 

 and at the bottom during 1909. 



Table giving the average number of bacteria in 

 the water of New York harbor during ebb and 

 flood tides during 1909. 



Averages of 1,082 examinations of water, made 

 for the Metropolitan Sewerage Commission of 

 New York, are included in the tables. 



Discussion of present dangers to the health of 

 the people from the vast quantity of sewage 

 dumped into New York harbor, with special refer- 

 ence to bathing and the oyster industry. 



Intensity of Pollution as shown by Numbers of 



Bacteria: Patn B. Parsons. 



A consideration of numbers of bacteria in vari- 

 ous sections of New York harbor, including a 

 comparison of the numbers occurring in samples 

 collected in the Atlantic Ocean and in those taken 

 at points where there was a high degree of pollu- 

 tion. 



Summary of the average number of bacteria in 

 each distinct section of the harbor, during ebb 

 and flood tides. 



Table showing average numbers of bacteria as 

 compared with the average per cent, of saturation 

 with oxygen in the water of the various sections 

 of New York harbor for all depths and tides dur- 

 ing 1909. Eight hundred oxygen and 1,082 bac- 

 terial analyses, made for the Metropolitan Sewer- 

 age Commission of New York, are included in the 



' See Journal of Infectious Diseases for 1910. averages. 



