The Birmingham age-herald., 1905-08-23

plants is to be commended, and is we think, worthy of note.
 The use of a coagulant to cause ad- hesion between the minute particles of clay In suspension, so that they may be more easily caught on the filter is essen tial in order to obtain the best results from filtration and is in keeping with the practice at all large filter plants and with the recommendations of experts The coagulant which is most generally used Is tho sulphate of aluminium, and this substance is the one in use at this plant. A water containing eight parts of alkalinity per million will completely de- compose one grain of coagulant per gall lon. But since the average alkalinty of the Cahaba water Is 42 parts and that of the North Birmingham water 122 parts per million, and since the average amount of coagulant is only 063 grains and 044 grains per gallon, respectively, it will be seen that both the waters could easily de- compose more than five times as much coagulant as is actually used in the pro- cess of purification.
 For purpose of comparison, your eon- mittee examined the reports on the bac- terial efficiency of the test filters at Gin cinnati and Louisville, where the quality of the filtered water had been pronounced satisfactory by boards of experts. Taking an average of 26 consecutive runs in each city we find the average number of bacteria per cubic centmetre to be 117 and 52 respectively. On the other hand we find the average number bac- teria per cubic centimetre in the filtered water of this city Is for the Cahaba plant and 10 for the North Birmingham plant. which compares most favorabY with the results obtained elsewhere, not only at the two cities mentioned, but with those of any public supply of which we have been able to get any informa- tion.
 At the request of the committee, pr. J. s. McLester kindly made a series of bac- teriological examina tions of the tap water. His report which we attach here to. shows substantially the same counts per cubic centimetre as those of MT. c. P. Nibecker quoted above. None of the specimens examined by him showed the presence of either the colon bacillus or the typhoid bacillus
 In conclusion. we would say that the water supply of this city more than meets all sanitary requirements and it's analv- sis Is not surpassed by that of any other public water supply of which we can find any record.
 JAMES BowRoN,
 Chairman.
 ERSKINE RAMSAY,
 R. 1T. PEARSON,
 W Y. KFTTTG.
 W. M. JORDAN.
 c. B. MCCORMACK
 McLester's Letter. Dr. w M. Jordan. Chairman. City: Dear Sir-Regarding your request that I make certain meteorological studies of the water supplied the city of Birming- ham. I beg leave to submit the follow ing:
 During a period of ten days twenty specimens of tap water were examined. Only organisms growing at body tempera- ture were sought
 From six to fourteen bacteria to the cubic centimetre were found.
 None of the organisms showed the acid forming or indol producing properties of the colon group.
 Certain of the bacteria were tested with typhoid blood for the aEglutinative phe- nomenon and all gave negative result One growth proved to be the bacillus pyocyaneus.
 I would remind you that these studies cover only a period of ten days. and do not aspire to the dignity of a finished re- search. Yours faithfully.
 JAMES s. MLESTER.