49 8 



NA TURE 



[March 26, 190^ 



the extent of the injury that would be inflicted on the objects 

 of such observations by a temporary interruption of the 

 same. A large number of the problems presented by the 

 physics of our globe can only be attacked with any hope 

 of success from this basis ; it is essential to have a number 

 of well supervised principal stations in each country supply- 

 ing an uninterrupted homogeneous series of observations. 

 These stations are also of service in the study of climat- 

 ological history, and are destined to prove of great import- 

 ance in the study of meteorology in the future. 



Only in a limited sense can we agree with Prof. Schuster's 

 dictum that before commencing to observe we should make 

 sure that our observations will prove of service, and will 

 give answer to a definite question. Not even in the case 

 of observatories do such instructions hold good. When 

 addressed to private observers we would characterise them 

 as " blinkers " which limit the range of vision to definitely 

 laid down lines. We quote one example : when Schwabe 

 began his sun-spot record, it must have appeared to 

 specialists as a mere hobby, devoid of all scientific objei t ; 

 had it been otherwise astronomers would undoubtedly have 

 commenced such observations earlier. And what scientific- 

 value have these observations now attained to? 



LEAD IN PEATY WATER. 1 



THE report under notice is a statement of the results 

 obtained from an examination of the water supplies 

 and their gathering grounds and storage reservoirs in 

 twenty-three more or less peaty collecting areas in York- 

 shire 'and Lancashire. The object of the examination was 

 to indicate the origin of the plumbo-solvent nature of these 

 waters, and the best methods of preventing or counteracting 

 tin- action before the water wa^ distributed to consumers. Dr. 

 Houston concurs with Mr. Ackroyd and with other chemists 

 who have studied the subject in these districts in attributing 

 the power of dissolving lead in dangerous quantity to the 

 presence in these waters of acids derived from the peat ; 

 and he further intimates his belief that the acid is produced 

 from the peat by the action of certain bacteria found in the 

 peat itself. He finds that the acid nature of the water is 

 frequently not indicated by litmus paper or by other 

 ordinary means, but that it is easily ascertained by the 

 change in colour produced in an alcoholic solution of lac- 

 moid. 



The " erosive " action which is exerted on dull lead by 

 dissolved oxygen is considered to be of relatively 'slight 

 importance, since, in the absence of peaty acids, the amount 

 of solvent action due to this cause is comparatively slight. 

 The peaty acids apparently produce soluble salts of lead and 

 cause the water to bring a much larger proportion of lead 

 into solution than could be introduced by the formation and 

 solution of the oxide alone. Peat is invariably acid in 

 reaction, and peaty water is also always acid. That the 

 solution of the lead by moorland water is due to the peaty 

 acids which it contains has been proved by direct experi- 

 ment. Further, a decrease of plumbo-solvent power is 

 noticed when these acids are reduced in quantity by various 

 natural causes, or by artificial neutralisation. Indeed, the 

 methods of counteracting plumbo-solvency in peaty water 

 which are adopted in the moorland districts consist in neu- 

 tralising the acids in the water with carbonate of soda, with 

 carbonate of lime, or with slaked lime. In this connection, 

 it should be remembered that the quantity of slaked lime 

 used must be carefully adjusted, since, when it is present 

 unaltered in solution in the water it promotes and does not 

 diminish the plumbo-solvent power. 



The variation in degree of solvent action shown by the 

 same moorland supply at different times is shown to be 

 connected with the varying proportions of acid peaty water 

 and of neutralising spring water which the supply contains. 

 In dry weather, the neutral and neutralising water pre- 

 dominates, while rainy weather tends to increase the pro- 

 portion of superficial acid water which comes out of the 

 peat ; these variations in composition markedly influence the 

 plumbo-solvent power of the water. 



The author appears to have confined his attention to the 



1 Thirtieth Annual Report of the Local Government Board, 1Q00-1901. 

 Supplement "On Lead Poisoning and Water Supplies." By 1 'r. Houston. 

 Pp. xi -t- 224. 



amounts of lead in solution in the water, and, undoubtedly, 

 these are the common sources of danger. But a not in- 

 considerable amount of lead may be removed from the metal, 

 and exist at first in solution as hydroxide, and subsequently 

 as a deposit of hydroxycarbonate, when pure soft water acts 

 on lead in the presence of the atmosphere ; in water supplies 

 this action is often considerably restricted by the presence 

 of carbonic acid in solution in considerable proportion, or 

 by the presence of silica, sulphate or carbonate in small 

 amount. 



The vast amount of detailed information contained in the 

 report is worthy of serious consideration by those who have 

 to deal with the supply of soft peaty water, as is also the 

 recommendation that the seasonal plumbo-solvent power of 

 the different sources from which any particular supply is 

 derived should be accurately known ; arrangements can 

 then be made either to avoid the collection of portions of 

 the supply at the times when they possess a dangerous 

 solvent power on lead, or to neutralise them by satisfactory 

 treatment before they are distributed to consumers. F. C. 



PROGRESS OF THE NEW VEGETATION OF 



KRAKATAO. 



TT is within a few months of twenty years since the great 

 eruption took place which absolutely killed all life in the 

 island of Krakatao. About three years later, Dr. Treub visited 

 the island and examined the beginnings of a new vegetation, 

 the results of which were recorded in 18S8 (Nature, vol. 

 xxxviii. p. 344). He found that the first vegetable settlers on 

 the covering of pumice-stone, lava and ash were microscopic 

 alga:- belonging to the Cyanophycca?. These organisms coveted 

 the surface with a slimy layer, which acted as a decomposing 

 agent and created a suitable substratum for ferns, of which 

 about a dozen species^vere already abundant in 1SS6. Dr. 

 Treub also observed a few individuals of fifteen species of 

 flowering plants, most of which had sprung from drift-seeds. 



In the spring of 1897, a paity of botanists visited the island, 

 and Dr. O. Penzig has published the results of their investi- 

 gations and observations {Annates du Jardtn Botanique de 

 B11itcn-.org, 2me serie, iii. (1002), pp. 92-113, with seven 

 views), from which we leatn that sixiy-two species of vascular 

 plants were observed on Krakatao and the neighbouring islets, 

 Lang and Verlaten. Fifty of these colonists are flowering 

 plants, representing twenty-one natural orders, and it seems 

 highly probable that they all reached the islands independently 

 of man. Classifying these fifty-three species according to the 

 assumed means by which their seeds were conveyed to the 

 islands, 7-54 per cent, were possibly carried by birds, 32^7 

 per cent, were probably wind-borne and 6CV39 per cent, were 

 almost certainly cast up by the waves of the sea. No additional 

 species of fern appears to have established itself in the islands 

 between 1886 and 1897. This is inexplicable, because the 

 region is tich in ferns, the spores of which, one would suppose, 

 would be brought by winds in abundance. Apart from ferns, the 

 probable " aeolophilous " element consists of eight Composite, 

 six grasses and four orchids. After passing the strand belt of 

 vegetation, which is by far the most numerous in species, dense 

 thickets of Phragmites, Saccharum and Gymnothrix were en- 

 countered. The interior and higher part of Krakatao is still 

 I much less covered with vegetation, ferns largely preponderating. 

 Conspicuous and relatively common amongst 'he flowering 

 plants was Spathiglotiis plicata, a terrestrial orchid. The other 

 orchids are Vanda Sulingi, Arundina speciosa and a species of 

 Phajus. Krakatao is about twenty niilesdistant from both Java 

 and Sumatra, and the most interesting question suggested by the 

 new vegetation is, Flow far does it afford a solution of the 

 problem of the origin of the vegetation of much more remote 

 islands which have more than a littoral or coral island flora ? 



W. BOTTING HEMSLEY. 



ANTHROPOLOGICAL NOTES. 



'T*HE strange cranial deformation known as trigonocephaly, 

 *■ in* which the forehead is constricted and more or less 

 pointed, and the temporal region and the ba>e of the skull are 

 broadened, is the subject of a research by Dr. M. Hanotte in 

 V Anthropologic (tome xiii. No. 5, p. 5S7). 



The weight of the human brain is the subject of a detailed 



NO. 1743, VOL. 67] 



