THE NEW ENGLAND STATES. 23 



in the raw or natural condition; hence additional care is necessary 

 in the bottling and vending of such a product. The ordinary methods 

 of bottle washing as employed at the present time are totally inade- 

 quate. All bottles should be properly sterilized subsequent to wash- 

 ing, in order to insure freedom from dangerous organisms. Realiz- 

 ing that many natural waters may be polluted, either directly from 

 farm waste or the sewage of densely populated localities or from 

 unclean bottles, it becomes necessary to examine such products for the 

 bacteria indicative of such pollution. 



The bacteriological methods of water analysis as followed by the 

 Bureau of Chemistry are essentially those recommended by the com- 

 mittee on standard methods of water analysis and adopted by the 

 American Public Health Association on January 9, 1905. 1 Slight 

 modifications from the original recommendations have since been 

 made, which include the use of ox bile containing 1 per cent of pep- 

 tone and 1 per cent of lactose, for the detection of B. coli types of 

 organisms and streptococci. Other minor differences in the methods 

 of procedure now used in this bureau will be mentioned under the 

 appropriate headings. 



COLLECTION, BOTTLING, AND SHIPPING OF SAMPLES. 



The minimum quantity of water for making the ordinary bac- 

 teriological examination should be 2 ounces. In special cases larger 

 quantities may be desired. Two and four ounce samples ware used 

 in conducting this investigation. 



Glass-stoppered, hard, clear, white glass bottles are most satisfac- 

 tory. Cork-stoppered bottles, earthen jugs, or metal containers 

 should not be used for this purpose. These bottles should be care- 

 fully cleansed each time before using by means of a sulphuric- acid- 

 bichromate mixture, or with alkaline permanganate followed by a 

 mixture of oxalic and sulphuric acids, and then by a thorough rinsing 

 with clean water. The necks and stoppers of sample bottles may be 

 protected from dirt by tying cloth or thick paper over them before 

 sterilization. 



The writer has devised a special aluminum container to hold and 

 protect samples, which consists of two cylindrical, threaded halves, 

 both of which are numbered for identification and for facilitating the 

 keeping of records. Both the bottle and the container are sterilized 

 and not opened until the sample is collected. 



Sterilization is perfected by the use of dry heat for one hour at 

 160 C., or in the autoclave at 115 C. for 30 minutes. Sample 

 bottles are transported by express in a wooden shipping case specially 



1 Report of the Committee on Standard Methods of Water Analysis to the Laboratory Section of the 

 American Public Health Association, presented at the Tlabana meeting January 9, 1905. Reprinted 

 from the Journal of Infectious Diseases, Suppl. No. 1, May, 1905. 



