226 



NATURE 



\_yuly 19, 1877 



(2) any sewage matter ; (3 any poisonous, noxious, or 

 polluting liquid from any manufacturing process ; and 

 (4) any poisonous, noxious, or polluting solid or liquid 

 matter from any mine. 



Mr. Higgins justly remarks that "the successful work- 

 ing of the Act will much depend upon the meaning of the 

 word ^polluting ' as therein used, by those with whom its 

 interpretation rests." In order to understand the drift of 

 this remark it is necessary to observe that the Act of 1876 

 yirtually gives no standard of purity, though the Commis- 

 sion of 1S68 recommended an extensive and somewhat 

 stringent list of standards. We think that on the whole 

 the Act is right in the omission, as a suggestion made by 

 Mr. Crookes in his evidence before the House of Lords in 

 1873, namely, " that the river itself should be the standard 

 of purity, and that no liquid should be allowed to be sent 

 into a river if the liquid contains a greater percentage of 

 impurity than the river itself," seems to be a very feasible 

 standard and one easily and quickly referred to. Again, 

 as Mr. Crookes pointed out, the standard would naturally 

 improve, as nothing worse than the river at any given 

 point would enter it, whence in the course of nature 

 amelioration would ensue, while the process being gradual 

 would give the manufacturer or township time to improve 

 their waste or sewage, and one of the most disastrous 

 sources of trouble the injury to the water-course from the 

 casting into it of solid refuse would be at once prohibited ; 

 as would pollution by actually poisonous matter, such as 

 arsenical and other liquids. 



It appears to us that guided by competent chemical 

 evidence there ought to be no difficulty in obtaining legal 

 decisions as to the polluting or harmless character of any 

 liquid that may be called in 'question, while as to solid 

 matters, of any kind whatever, the mere fact of their entry 

 into a stream ought to be an offence without reference to 

 their character. On the whole we think the act, though 

 perhaps partaking too much of the " permissive " cha- 

 racter, which is so prominent a feature of modern legisla- 

 tion, to be one which, if conscientiously used with due 

 consideration to the facts of each individual case ought 

 to work great good. In the race for wealth we are 

 perhaps too little apt to think of the future. The brooks 

 and lunning streams like the land we live on are not ours 

 to do as we like with, but like an entailed estate are only 

 held in trust for the next heir, and like national or family 

 honour should be handed down to posterity pure and 

 unsullied. 



Mr. Higgins has devoted great care to his treatise on 

 the Act, and his chemical training has evidently stood 

 him in good stead, the numerous references to cases 

 bearing on the various points show a laborious study of 

 the legal aspects of the case and will add greatly to the 

 value of the work in the eyes of the legal profession, for 

 whose information it is primarily intended. 



R. J. FRiswaLL 



OUR BOOK SHELF 



The Cradle of the Blue Nile; a Visit to the Coutt of 

 ^'"g John of Ethiopia. By E. A. De Cosson, 

 F.R.G.S. Two vols. With Map and Illustrations. 

 (London : John Murray, 1877.) 



Although Mr. De Cosson did not go over any new 

 ground in his tour, and although he was unable even to 



carry out his original plan, we are sure that most readers 

 will find much that is new and certainly interesting in his 

 volumes. He went slowly southward from Massowah to 

 Lake Tzana, north-west to the lower Bahr-el-Azrek, down 

 the Nile to Berber, and across to Saakim. He won the 

 favour of King John, of whom he speaks as an able, well- 

 meaning ruler, and was thus able to see much of the life 

 of the people, and learn much of the antiquities and the 

 character of the coun'ry that otherwise he would have 

 missed. To any one wishing to obtain an attractive 

 account of the past history and present condition of 

 Abyssinia, we strongly commend Mr. De Cosson's work. 



The Tiber and its Tributaries, their Natural History 

 and Classical Associations. By Strother A. Smith, 

 M.A. Map and Illustrations. (London : Longmans 

 and Co., 1877.) 



The idea of this work is, we think, a happy one, and its 

 execution successful. The object is to gather under one 

 head everything of interest relating to the Tiber. This has 

 necessarily involved a great amount of research, and the 

 result will be welcomed both by the student of history, 

 the " scholar," and the geographer. Considerable space 

 is devoted to the inundations of the Tiber, and also to its 

 birds and its fishes. Two nicely-coloured plates are 

 devoted to the mura?na, the mullet, the lamprey, and the 

 sturgeon. The Tay, at Perth, we should inform Mr. 

 Smith, is no more an "estuary" than the Thames at 

 London Bridge, unless the word is applied to all that part 

 of a river reached by the tide. 



A Short Account of the Principal Geometrical Methods 

 of Approximating to the Value of rr. For the Use of 

 Colleges and Schools. By the Rev. G. Pirie, M.A. 

 (Macmillan, 1877.) 



Elements of Geometry Based on Euclid. Book I. For 

 Elementary and Middle Class Schools. By E. Atkins, 

 B.Sc. Collins's fichool Series. (Glasgow: Collins, 1877.) 



Takiinetry. Concrete Geometry in Three Lessons. Ac- 

 cessible, Inaccessible, Incalculable. Translated by D. 

 W. Gwynne, M.D., from the French of E. Lagout. 

 (Glasgow: Collins, 1877.) 



The little pamphlet first named does not attack theproblem 

 from the circle-squarer's point of view — the use of the word 

 "approximating'' sufficiently points this out — but gives an 

 interesting account of what was done for the question 

 between the times of Archimedes and Huyghens. A few 

 elementary propositions lead up to what was attempted 

 by Willebrord Snell ("Cyclometricus," i62i)and elegantly 

 effected by Huyghens. Mr. Pirie's object is to correct 

 what he deems a defect in our present works on Trigono- 

 metry, and to supply a few simple propositions " on the 

 threshold of the subject." We can recommend the book 

 as one suitable for being put into the hands of sixth form 

 pupils. A few references are supplied to fuller sources of 

 information upon the quadrature of the circle. 



Mr. Atkins's book seems to differ but little from the 

 ordinary forms of Euclid as now printed. One feature 

 is the addition of short side-notes drawing attention to 

 the objects of the successive steps of the construction and 

 proof. There is a short collection of sixty exercises 

 grouped under the propositions upon which they depend. 

 Some of these appear to us wrongly placed, and a few 

 incorrectly printed. The work is neatly got up and of a 

 handy form. 



If all that is said of takimetry by its admirers be true 

 a revolution in mathematical instruction may be speedily 

 expected. " With one hundred lessons of takimetric 

 instruction any one can very well learn geometry, algebra, 

 arithmetic, and mechanics." " The classical geometry of 

 Euclid disi^uises its object, its utility, and thus, for a con- 

 siderable time, yields a barren and discouraging result, 

 v/hilst takimetry is able, on the other hand, to produce 



