314 



NATURE 



[July 31, 1890 



"youth there— frequently corresponded with Lavoisier, and 

 next to his friend Hutton there was probably no one who 

 knew more of his opinions on current scientific topics. We 

 have it on the authority of Thomas Thomson that Black 

 felt hurt at the publication of several of Lavoisier's 

 papers in the Meinoires de V Academic, without any 

 allusion whatever to what he himself had previously 

 done on the same subject. Thomson adds, however, 

 that, " from the posthumous works of Lavoisier, there is 

 some reason for believing that, if he had lived, he would 

 have done justice to all parties ; but there is no doubt 

 that Dr. Black, in the meantime, thought himself 

 aggrieved, and that he formed the intention of doing 

 himself justice by publishing an account of his own 

 discoveries ; however, this intention was thwarted and 

 prevented by bad health" ("History of Chemistry," 

 vol. i. 330). 



We have ventured to say this much in justice to Black, 

 not because we wish in any way to disparage Lavoisier, 

 or to minimize the greatness of his services to the philo- 

 sophy of chemistry, but because we think that M. 

 Berthelot has allowed his analogy to run away with him. 

 To say that Lavoisier was the actual author of la 

 revolution chimique is hardly more true than the 

 statement that Marat was the author of the Revolution 

 of 1789. The learned author of the" Introduction a la 

 Chimie des Anciens et du Moyen Age" stops short of 

 attempting to prove the truth of Wurtz's saying that 

 " chemistry is a French science ; its founder was 

 Lavoisier of immortal memory ; " but we cannot help 

 thinking that the circumstances under which his book 

 was produced have in some measure warped his critical 

 faculty ; and that, seduced by analogy — that fruitful 

 parent of error — he has been led to claim for his hero a 

 pre-eminence in the creation of the new order of things 

 that the unbiassed historian could not possibly grant. 



T. E. Thorpe. 



THE ORGANISMS INFESTING WATER- 

 WORKS. 

 Die Pflanze7i und Thiere in den dunkeln Rdumen der 

 Rotterdamer Wasserleitung. Bericht iiber die Biolo- 

 gischen Untersuchungen der Crenothrix-Commission zu 

 Rotterdam, vomjahre 1887. Erstattet von Hugo de 

 Vries. (Jena: Gustav Fischer, 1890.) 



THE water-works of Rotterdam obtain their supply of 

 water from the River Meuse, and apparently were 

 able to filter and purify it in a satisfactory manner until 

 the spring of 1887, when the Schizomycete Crenothrix 

 Kiihniana made its appearance in great abundance in the 

 various reservoirs and aqueducts. This gave rise to so 

 much trouble and difficulty in obtaining a pure water- 

 supply, that new and improved filters were made, and 

 finally a Commission of investigation was appointed, which 

 carried on its work chiefly during the winter 1887-88. 

 Some further questions bearing on the matter were 

 investigated in the following year, and now we have 

 before us the chief scientific results of the Report sent in 

 by the Professor of Botany at Amsterdam, Hugo de 

 Vries, and giving a most interesting account not only of 

 this particular pest, the Crenothrix, but also of the other 

 NO. 1083. VOL. 42] 



plants and animals found living in the dark places of the 

 Rotterdam aqueducts. 



A small laboratory was fitted up in the water-tower, of 

 one of the reservoirs, so that Prof, de Vries and Dr. F. 

 Dupont, who conducted the microscopical investigations, 

 might have every opportunity of examining the plants 

 and animals in a living condition. In the first part (50 

 pages) of the paper the attached organisms found in the 

 aqueducts in 1887 are described, beginning with Creno- 

 thrix Kiihniana (one of the " iron-bacteria "), of which a 

 full account, with figures, is given. This organism was 

 found to be undoubtedly the chief cause of the impurity 

 of the Rotterdam water-supply, as it also had been in the 

 case of the "water-calamity" of Berlin in 1878. Its 

 powers of reproduction are so enormous that in a very 

 short space of time it can spread in abundance over a 

 wide area and render a vast amount of water impure. 

 De Vries comes to the conclusion from his observations 

 that Crenothrix does not vegetate in the soil, as had been 

 supposed to be the case by Brefeld and Zopf in the 

 Berlin investigations, but is derived merely from the 

 basins and canals of unfiltered water. 



The fixed plants and animals — (i) in the Meuse and in 

 the open basins, (2) in the covered-in canals for the un- 

 filtered water, and (3) in the dark chambers containing 

 the purified water — are successively described, and various 

 interesting observations noted. Spongilla {Meyenia) 

 fluviatilis was found, in the dark passages, covering the 

 walls in a thin layer, and was of a white colour, in place of 

 being green as it is when exposed to the light. The fresh- 

 water mussel, Dreyssena polymorpha, and the hydroid 

 zoophyte Cordylophora lacustris were found in great 

 abundance in some parts; lower worms, Rotifers, Infusoria, 

 some Crustacea, and a few Molluscs in others ; and ;i 

 luxuriance of fresh- water Polyzoa of the gentra. Plwnatella 

 and Paludicella in other parts of the system — over 30 

 species in all being observed, and these very much the 

 same forms which Kraepelin had found in the Hamburg 

 aqueducts, and Potts in those of Philadelphia — while 

 Cretiothrix was. present everywhere, apparently covering 

 everything in great abundance. In the filters, however^ 

 and in the channels containing filtered water, only Creno- 

 thrix and a few other Algae were found. The Sponges, 

 Zoophytes, Polyzoa, and Molluscs were entirely absent. 



The second part of the work deals with the free- 

 swimming animals — the fresh-water Crustacea. Of these, 

 two species, Asellus aquaticus and Gammarus pulex 

 unlike the attached animals (Polyzoa, &c.), are able to 

 penetrate into the filtered waters along with the 

 Crenothrix; and in 1887 these Crustaceans developed in 

 the purified water to such an extent as to be a perfect 

 plague, thus giving an excellent example of the rate of 

 increase of a species unchecked (for a time, at least) by 

 coriipetition. The Gammari and Aselli which penetrated 

 to the filtered waters had the field to themselves, they had 

 found a niche of nature previously unoccupied by any 

 animals, they had food and other conditions necessary for 

 life, and plenty of room, so they increased with astonishing 

 rapidity. 



In regard to their nourishment, the Gattitnari were 

 found by de Vries to subsist upon the Crenothrix, which 

 they thus to some small extent helped to keep 

 down ; while the Asellus, as was proved by an. 



