132 THE AMERICAN MONTHLY [May, 



of the total solids and the total organic matter, this latter deter- 

 mination being absolutely without reference to the question of 

 quality. The recent examination of a large number of published 

 analyses has forcibly impressed upon the writer the almost entire 

 lack of appreciation of a necessity for information as to what may 

 be termed the detail of the organic constitutents which prevailed 

 as recently as thirty to forty years ago. 



A few far-seeing students had, indeed, perceived clearly that the 

 current analyses of the day were considerably short of revealing 

 the thing necessary to be known, namely, what may be termed 

 the natural history of potable water. Chief among such must be 

 mentioned Dr. Hassall. whose illustrated memoir on the water 

 supply of London was published in 1S50. This, however, was 

 too far in advance of the day of its publication, and stood alone 

 for twenty years as the first guide-post on a new road to a more 

 exact knowledge of the detail of the natural history of potable 

 water. 



In the meantime a number of eminent chemists had clearly 

 perceived the necessity for additional information in regard to the 

 condition of the contaminating organic material more or less 

 present in all waters, and various refinements in chemical meth- 

 ods of study were accordingly made : for instance, the distinction 

 between the free and the albuminoid ammonia of the Wanklyn, 

 Chapman and Smith process ; the distinction between the organic 

 carbon and the organic nitrogen of Frankland's combustion pro- 

 cess, etc. Without going too much into the detail, let us consider 

 some peculiarities of the combustion process which are of his- 

 torical value in the present connection and at the present time. 



Probably, among the working water analysts of two decades 

 ago, Dr. Frankland perceived, more clearly than any other, the 

 necessity for distinguishing between the contamination resulting 

 from the waste products of animals, etc., and that produced either 

 by purely vegetable growth in water itself, or by surface water 

 coming in contact with vegetable matter in its ordinary course or 

 flow ; hence we find as distinctive features of the combustion 

 process the determination of the organic carbon, the organic nitro- 

 gen, and the estimation of the previous sewage or animal con- 

 tamination, a knowledge of these three together v\^ith that of the 

 free ammonia, nitrites, nitrates, and chlorine constituting in Dr. 

 Frankland's view a nearly complete natural history of water. 



With regard to the organic carbon and the organic nitrogen, 

 Dr. Frankland remarks in the Sixth Report of the Rivers Pollu- 

 tion Commission (1874) that the animal or vegetable origin of 

 the organic matter contained in potable water may, in most 

 cases, be judged by the relative proportions in which the two 

 elements, carbon and nitrogen, occur in the organic matter, and 

 that in waters contaminated by organic matter "■ the smaller the 

 absolute quantity of organic nitrogen, and the less the proportion- 

 ate amount as compared with organic carbon, the better is the 



