470 APPENDIX 



scopically to ascertain if the bacillus is motile or not (or spore-bearing), 

 and it is then treated by Gram's method to ascertain whether it retains 

 the stain. The results being recorded, (d) The turbid fluid is used to 

 inoculate Litmus milk, for acid and clotting ; glucose- neutral-red agar, 

 for gas and fluoresence ; gelatin (stab or streak), for absence of liquefac- 

 tion ; and peptone solution, for indol. If the B. coli is present, all the 

 reactions indicated, with the possible exception of the production of 

 fluorescence, will be produced. by one or more of the colonies selected. 

 The water is tested for the presence of B. enteritidis sporogenes in the 

 ordinary way. It should be added that such an examination as the 

 above fails to obtain information upon the general constitution or the 

 bacteriological flora of a water which is obtained by the additional 

 means of the gelatine plate method, and whilst of value for rapid use, 

 should not be substituted for the systematic study of a water. 



REPORT OF THE COMMITTEE APPOINTED BY THE ROYAL INSTI- 

 TUTE OF PUBLIC HEALTH TO CONSIDER THE STANDARDISA- 

 TION OF METHODS FOR THE BACTERIOSCOPIC EXAMINATION 

 OF WATER, 1904. 



All the members of the committee are in agreement that the minimal number of 

 procedures should be : 



(a) Enumeration of the bacteria present on a medium incubated at room 



temperature (18-22 C.). 

 (6) Search for B. coli, and identification and enumeration of this organism if 



present. 



The committee regard these procedures as an irreducible minimum in the 

 bacterioscopic analysis of water. The majority of the committee recommend in 

 addition : 



(c) Enumeration of the bacteria present on a medium incubated at blood-heat 



(36-38C.). 



(d ) Search for and enumeration of streptococci. 



The committee do not think it necessary as a routine measure to search for the 

 B. enteritidis sporogenes, but are agreed that in special or exceptional instances it 

 may be advisable to look for this organism. 



The Collection of the Sample. No special precautions beyond those generally 

 recognised are suggested for taking the sample. The samples should be collected 

 in sterile stoppered glass bottles having a minimal capacity of 60 c.c. In special 

 instances it may be desirable to have much larger quantities. 



Unless examined within three hours of collection the sample must be ice-packed. 



(The committee recognise that under all circumstances the sooner the water is 

 examined after collection the more reliable are the results obtained.) 



Media to be employed for Enumeration. The choice of medium lies between 

 distilled-water gelatin, nutrient gelatin, distilled- water agar, gelatin agar, and 

 nutrient agar. The reaction of the medium is of importance. 



For enumeration at room temperature, any of these media may be employed ; 

 but for enumeration at blood-heat, an agar or gelatin agar must be used. 



The Americans seem to be using an agar medium only, and although on the 

 ground of simplicity it might be desirable to use a single medium for enumeration 

 under all circumstances e.g. a distilled-water agar it is felt by the committee 

 that gelatin media frequently give indications of value that are lacking with agar 

 vi/., liquefaction of the medium by many organisms and the more characteristic 

 appearance of the colonies in it ; gelatin is therefore recommended. 



Since with a polluted water (detection of pollution being the ultimate aim in 



