June 19, 1884] 



NA TURE 



167 



waters with which not a few towns in the North of England 

 are supplied, act upon the leaden service-pipes to such an 

 extent as to become dangerous. It may even be ques- 

 tioned whether an occasional epidemic of fever is not a 

 smaller evil than the continued occurrence of lead-poison- 

 ing. The use of iron service-pipes, or of lead thickly 

 lined with tin, is troublesome and expensive. Perhaps 

 sooner or later some unobjectionable material may be 

 found to take the place of lead in the manufacture of water- 

 piping. 



A well-known authority on water analysis reminds us 

 that waters from the mountains of Wales, Cumberland, 

 &c, may possibly hold lead and copper in solution, and 

 one has been found to contain appreciable quantities of 

 arsenic. Great care would therefore be necessary in the 

 selection of a supply from such districts. 



The hardness of the New River water, of that furnished 

 by the Kent Company, and indeed of the London water- 

 supply in genera], has often been complained of, and the 

 softness of the northern waters has been urged in their 

 favour. It is, however, by no means certain that from a 

 sanitary point of view a soft water deserves the preference. 

 Many medical authorities contend that a water of 

 moderate hardness is preferable, for dietetic consumption, 

 to such waters as are supplied to Huddersfield, Leeds, 

 Manchester, &c. It is urged, not without a show of pro- 

 bability, that a supply of calcareous salts in drinking-water 

 is especially advantageous in the formation of the bones 

 of young children. Dr. C. Cameron of Dublin, however, 

 maintains that there has been an improvement in the 

 public health of Dublin since the soft water of the Vartry 

 was substituted for the hard water with which that city 

 was formerly supplied. Further inquiry, therefore, is 

 necessary in this direction. It seems to us, however, that 

 there is hardness and hardness. The hardness of water 

 may be due to lime salts or to magnesian compounds. 

 For the latter there is comparatively little need in the 

 human system, and their regular ingestion is found un- 

 favourable to health. But to condemn any water as pre- 

 judicial merely on the ground of hardness seems to us rash 

 in the extreme, in view of the high standard of health 

 existing in districts where hard waters only are available. 



It has been proposed to increase the London supply by 

 means of a system of artesian wells. Unfortunately, 

 though a single such well may yield a large and continu- 

 ous supply of water, this quantity cannot be multiplied by 

 sinking similar wells in the neighbourhood, as has been 

 found in the case of the celebrated well of Grenelle- 

 Among the many schemes enumerated by Mr. Bevan, 

 there is one prominent in its singularity. Shafts were to 

 be sunk down to the chalk on each side of the Thames 

 every quarter of a mile. Each such shaft was to have a 

 canal communication with the river between high and low 

 water mark, through which these shafts were to be filled 

 with water. At some distance from each descending 

 shaft another was to be sunk, into which the filtered water 

 would flow as in an inverted siphon, until it rose to the 

 level of the river. The water of deep wells is in general 

 remarkable for its freedom from organic pollution. But 

 this purity probably depends on the slowness of the filtra- 

 tion by which they are supplied. 



Our author, after giving the details of a great number of 

 projects, comes to no decided conclusion. He remarks 



that one of them will ultimately be adopted for the very 

 good reason that a change of some kind will eventually be 

 necessary. But he judiciously adds, " It need not be 

 looked upon as in any way superseding the arrangements 

 of the present supply." 



FLOWERS AND THEIR PEDIGREES 

 Flowers and their Pedigrees. By Grant Allen. (London : 

 Longmans, Green, and Co., 18S3.) 



THIS book consists of eight short essays on the evolu- 

 tion and distribution of plants which originally 

 appeared as articles in several of the London magazines, 

 supplemented with an introductory chapter. Two of 

 these essays treat of the reasons for the presence of 

 certain plants in our insular flora, as illustrated by the 

 Hairy Spurge {Euphorbia pilosa, L.) and the Mountain 

 Tulip {l.loydia serotina, Rchb.). The remainder discuss 

 the evolution of certain types of plants, the examples taken 

 being the daisy, strawberries, cleavers, wheat, the family 

 of Rosacea;, and the cuckoo-pint. The articles are written 

 in the author's well-known pleasant style, and cannot fail 

 to attract and interest many who have never previously 

 turned their attention to the study of our common weeds. 



Mr. Grant Allen has a great horror of a " microscopical 

 critic," which he defines as "a learned and tedious person 

 who goes about the world proclaiming to everybody that 

 you don't know something because you don't happen to 

 mention it." After reading this book, however, one feels 

 tempted to reassure him on this head. For the work 

 contains a considerable number of things which we may 

 venture to state nobody ever knew before. Take, for 

 instance, the text of the fifth essay, that on the origin of 

 wheat : " Wheat ranks by descent as a degenerate and 

 degraded lily " ; and again, " While the daisy has gone 

 constantly up and while the goose-grass has fallen but a 

 little after a long course of upward development, the 

 grasses generally have from the very first exhibited a 

 constant and unbroken structural decline." This, we 

 think, will be an entirely new view to the botanical mor- 

 phologist. On these lines he proceeds to trace the evolu- 

 tion of the wheat-plant, from an imaginary primitive 

 Monocotyledon, and suggests that Alisina ranunculoides 

 might represent the earliest petal-bearing type in this line 

 of development, except for the fact that its petals are 

 pinky-white instead of yellow ! From this plant he traces 

 the descent of the wind-fertilised rushes, the stamens of 

 which he states hang out pensile to the breeze on long 

 slender filaments. This is certainly not the case : the fila- 

 ments of the rushes are short and rather broad, and the 

 anthers are usually fixed by the base, and not at all more 

 adapted for wind-fertilisation than those of such a plant 

 as the bog-asphodel, which is regularly fertilised by 

 insects. 



From the rushes both the sedges and grasses are 

 derived, but on different diverging lines. The former 

 class of plants Mr. Grant Allen considers to be very 

 degenerate in type, the calyx and petals, which were 

 brightly coloured in the lilies, being reduced to the six 

 small dry bristles which we find in some species of 

 Scirpus. He does not explain, however, how it is that 

 some Cyperaceous plants possess seven or eight of these 

 bristles. But the most extraordinary suggestion is that 



