1 



460 Froceediinj-s uf the Rvyal Iri--ili Academy. 



The average of free ammonia from tlie four samples of the river is 

 0-0982, or under -iV of a grain in the gallon ; the average of albuminoid 

 ammonia from the same is 0-0779, or under ^ of a grain in the gallon. 

 It may be interesting to note that the examination of the river 

 water referred to as having been made by other -workers in the College 

 of Science Laboratory in 1874, gave a result equal to my average in 

 1875 : thus shewing a remarkable constancy in the state of the Liifey. 

 It may also be remarked in passing that my average for free am- 

 monia is less, but for albuminoid ammonia is greater, than the average 

 Messrs. "Wanklvn and Chapman reported as that of the Thames at 

 London-bridge, in June, 1867 : that river, the tide being at two hours 

 flood, yielding free ammonia = 0-12 82 of a grain per gallon ; and albu- 

 minoid ammonia = 0-0245 of a grain to the gallon. 



The average of free ammonia obtained from the ^9 street waters 

 is 17 grains to the gallon; that is, over 170 times the like average 

 from the river. The average of albuminoid ammonia fi'om the street 

 Avater is 3 grains to the gallon, or 38 times the Liffey average. 



It will be seen by the Table, that from three out of the f oui' river 

 samples, the quantity of free ammonia was under that yielded by any 

 of the street waters, except at Stephen' s-green, East and South. 



The maximum of free ammonia from the river -was at Burgh- quay, 

 and only reached 0-175, or less than i of a grain to the gallon ; whilst 

 the maximum of free ammonia from the street waters, namely, at 

 Moss-street and Poolbeg-street, was 105 grains to the gallon, that is 

 exactly 600 times greater than the river maximum. 



The least impure of the 29 street waters yielded nearly three times 

 more albuminoid ammonia than the most impure sample of the river 

 ■water ; for instance, the surface-water at Merrion-square, South, 

 being the best of the street waters, yielded 0-280 of a gi-ain, against 

 that obtained from the river at its worst, namely, 0-098 of a grain, or 

 nearly 3 to 1 . 



But the bad preeminence of the water in Moss-street and at 

 Peter-place (corner in Adelaide-road^:, and in Lee's-lane, off Aston's- 

 quay, namely, 10 and 10-15 and 11-2 gi-ains of albuminoid ammonia 

 from one gallon of each water, respectively, is more than 100 times 

 greater than the Liifey maximum. 



Messrs. T\'anklyn and Chapman conclude from a wide induction 

 of experiments that ■' the disintegrating animal refuse in the river 

 [Thames] would be pretty fairly measured by ten times the albuminoid 

 ammonia which it yields." In this way, the average of such refuse 

 in the Liifey is 0-779, or just f of a grain in the gallon ; whilst the 

 average of such refuse in the street waters is 29 grains to the gallon. 

 That much of this enormous amount of animal matter thus in our 

 midst must, if not rapidly removed, take forms that will vaporise, 

 seems all but certain, since the conditions for spontaneous decompo- 

 sition may be said to be always present : there are the moisture and 

 heat requii'ed for this chemical change, and then there occurs at in- 

 tervals the drying up of these stagnant pools. 



