December 28, 1899] 



NA TURE 



J05 



other changes, its salinity then increasing by evapora- 

 tion. Brackish springs are common in the vicinity, and 

 these, with the salts of the feeding streams, still con- 

 tribute to the accumulation of saline matter. On the 

 authority of the United States Geological Survey, the 

 present rate of accumulation will charge the lake with 

 common salt within a period of 25,000 years. The 

 present density is about ri68, while that of the ocean 

 IS but 1-025. It appears that it is not the nature of the 

 saline materials, but their excessive quantity alone, that 

 makes the water unfit for ocean life ; for the relative 

 proportions of the solids m solution do not differ 

 materially in the lake-water and sea-water. Three-fourths 

 of these solids are common salt in both cases. The lake, 

 while strongly salt, is not alkaline, and would presum- 

 ably support the higher organisms of the ocean if properly 

 diluted. Diatoms have been grown experimentally in 

 the diluted Salt Lake water, and, indeed, have been 

 found native in the lake, together with other low plant 

 and animal life, in its brackish parts. 



On account of the removal for commercial purposes of 

 large quantities of salt, many have looked forward to a 

 day when the consequent freshening process shall have 

 reduced the density of the water, sufificiently to make it 

 an inhabitable medium. About 42,000 tons of common 

 salt are removed annually, while 16,000 tons, according 

 to the calculation of the 25,000 year period required to 

 saturate the lake, enter it each year. From the present 

 density, i"i68, the lake must now hold about 400,000,000 

 tons of salt, and with these figures as a basis, it appears 

 that in 14,000 years— the processes continuing at the 

 present rate— the lake-water will reach the density of sea- 

 water. As this is a far cry into the future, some would 

 believe that the solution of the problem was to be found 

 in acclimatisation of marine forms to the present briny 

 waters. There is no evidence that this is feasible or re- 

 motely possible ; the oyster has the best possible oppor- 

 tunity to adapt itself to salt or fresh water, but clings to 

 an intermediate brackish zone of a density between 

 roio and 1020. The plan which seemed to offer the 

 only possibility of success concerned the oyster, and 

 the location, near the mouths of the fresh streams 

 that feed the lake, of water-zones of a degree of 

 brackishness favourable to oyster growth. The conditions 

 which were found to exist were such as to show 

 conclusively that there is no hope for the utilisation of 

 the lake in this way. The favourable zones, which are 

 narrow at best — in no case over three hundred yards — 

 are subject to great fluctuations in position due to the 

 wind and to seasonal changes. The variation in the 

 volume of water carried by the inflowing streams is re- 

 markable. In one of them the ratio of the greatest 

 flow to the least was as 28 to i. When they 

 are flushed with the melting of snow in spring the 

 oyster zone is carried lakeward, and during the period 

 of minimum flow in autumn it travels up the mouth of 

 the stream in which it is located. The wind alone some- 

 times makes a change of level of several feet, and a 

 consequent change ot density from 1009 to 1-014 within 

 live mmutes has been observed. Moreover, the deltas 

 of the streams, which must of necessity be the location 

 of the oyster beds, are subject to deposits of silt in 

 amounts fatal to oysters. All these conditions in 

 conjunction make the difficulties of successful oyster 

 culture insuperable. 



The brackish springs characteristic of the Bonneville 

 bed have a low density, none exceeding i '005, and sug- 

 gest a plan by which they might be utilised. By making 

 them the sources of artificial ponds the evaporation, 

 which is greater than the rainfall, would raise the density 

 to the desired point at which it could be maintained by 

 a proper regulation of the brackish inflow and outflow. 

 On a commercial scale, however, the experiment would 

 be expensive, and might or might not justify itself. 

 NO. 1574, VOL. 6f] 



PAUL^KNUTH. 



DORN on November 20, 1854, Paul Erich Otto VViIhelm 

 -L^ Knuth, Professor at the Oberrealschule of Kiel, was 

 only in his forty-sixth year at his death on October 30. 

 After graduating at Griefswald in 1876, he was engaged 

 in teaching at Iserlohn in Westphalia, and from 1881 at 

 Kiel. His first scientific investigations were in the realm 

 of organic chemistry, his chief works a Handbook of 

 Flower-Biology, a Flora of Schleswig-Holstein, and a 

 series of short papers upon the botany of the islands off 

 the German coast — Riigen, Heligoland, Sylt, &c. 



The " Handbuch der Bliilenbiologie " is based on the 

 English edition of Hermann Midler's " Befruchtung der 

 Blumen," and is destined to replace it. Increasing know- 

 ledge has swelled the literature-list from 825 entries to 

 2871, and Knuth's plan allowed for three volumes in the 

 place of the single one issued in English in 1883 ; of these 

 the last, designed to contain all we know of the fertilisa- 

 tion of flowers in lands outside Europe, remains unpub- 

 lished. There is hope that the work may yet be completed . 

 Knuth's own observations in Java, Japan, and California, 

 made in 1898 and 1899, were made to add to the rather 

 meagre knowledge available for this unpublished 

 volume. 



His observations on the flora of the North Friesian 

 Islands, of Heligoland and ofRugen, demonstrate how the 

 winds that blow over sea-girt islets, inimical to insect life, 

 impose a limit to the distribution of plants whose highly 

 specialised flowers need insect aid for their fecundation. 

 1 he lesser the island the greater the influence. Riigen is 

 large, and it is not evident ; the Halligen are small, and 

 it is very apparent. These Halligen are "low-lying, 

 marshy islets, hardly rising more than a metre above high 

 tide, wind-swept, where one wanders hour after hour 

 without taking a smgle anthophilous insect, save on the 

 rare hot and windless days which coax a few to fly from 

 flower to flower." On them the high-types of floral 

 development are rare. 



His Flora of Schleswig-Holstein, named above, was 

 largely a compilation, intended to supply a real need, and 

 was followed by a History of Botany in the double 

 province. These, however, as the first steps towards his 

 botanical work, have their own interest. I. H. B. 



NOTES. 



Some particulars concerning the vessel which is being built at 

 the Howaldt Shipbuilding Yard at Kiel, for the German 

 Antarctic expedition, are given by the Berlin correspondent of 

 the Times. The ship will be built of wood, the only material 

 strong and elastic enough to resist the pressure of the ice. , In 

 form she will be somewhat rounder than the Fram, and will not 

 fall away towards the keel in the same manner. The length of 

 the ship will be about 46 metres, the breadth between 10 and 1 1 

 metres, and the draught about 5 metres. She will be con- 

 structed to carry coal and other stores sufficient for three years, 

 and will contain accommodation for five scientific observers, 

 five officers, and a crew of about twenty men. Each of the 

 observers, and each of the officers, will have his own cabin. 

 The centre of the ship will be occupied by. the rooms for 

 scientific work, and the forecastle will contain space for fifty 

 Arctic dogs. The ship will be rigged as a three masted 

 schooner. Two steam winches will serve the anchor and will 

 also be used for scientific purposes. The ship will be illu- 

 minated throughout with electric light. The Howaldt Ship- 

 building Yard, which is under a contract to have the ship built 

 by May i, 190 1, and fitted out not later than the end of August, 

 1901, has already begun the construction. A model of the 

 vessel will be shown at the Paris Exhibition. 



