A^ov. 26, 1885] 



NATURE 



91 



wlielher such an ice-cap increased by more than three or four 

 inclies yearly, so that from 3000 to 4000 years might easily have 

 elapsed since the incipient birth of the berg in question. Lieut. 

 Greely advocated future Arctic exploration in the direction of 

 Franz Jcsef Land. 



M K. Gamel, at whose sole expense the late expedition to the 

 Kara Sea, under Lieut. Hovgaard, was undertaken, intends, 

 provided his enterprise be seconded by the Government, to send 

 his steamer Dijviplina next summer on an expedition, under an 

 officer of the Danish Koyal Navy, to the east coast of Green- 

 land, to explore and lay down the coast-line between 66°'o8, 

 the farthest northward point attained by Capt. Holms's expedi- 

 tion, and 70°. 



According to the Gaz-.tte Geogi-aphique, M. MoUer, who was 

 recently charged with a mission of botanical investigation to the 

 Island of St. Thomas, has returned to Lisbon. He has brought 

 with him a large number of interesting specimens, not only of 

 the botany, but also of the geology, of the island. These have 

 been placed for investigation in the hands of M. Henriques, the 

 Professor of Botany of the Coimbra University. M. MoUer 

 has also made some important additions to ancl corrections in 

 the map of St. Thomas recently published. He has proved 

 that the highest mountain in the island is the Peak of St. 

 Thomas, and that its height is 2142 metres. 



An officer of the French Nav)', Commander Reveillere, has 

 succeeded in a daring attempt which he made recently to ascend 

 the rapids of the Meikong, beyond Sambo j, in a steamer. 

 Samboc is the chief Cambodian town on the river, and at one 

 time it was thought impossible for a steamer even to reach that 

 point. A short distance above the town commences a series of 

 rapids, which last for about forty miles, and which in parts 

 apjiear as formidable obstacles to navigation as the cataracts on 

 the Nile. Commander Reveillere, however, succeeded in over- 

 coming them, but only after such exertion and danger as make 

 it clear that in their present state they present an insuperable 

 barrier to navigation for commercial purposes. He proposes a 

 thorough hydrographic study of this section of the river at low 

 water, and he is convinced that the famou; barrier will turn out 

 to be merely a mass of trees which has got permanently fixed 

 there and is maintained by annual additions, but which cm be 

 ■ removed without difficulty by means of explosives. Beyond the 

 rapids is the town of Stung-Treng, where the greater part of 

 the commerce of the Laos reaches the river, and hence the 

 advantage of a navigable passage. Commander Reveillere 

 concludes his account of his feat by recommending "a 

 serious hydrographic campaign in the rapids of the Meikong, 

 and in the lower Laos." The Meikong is one of the greatest of 

 the great rivers of Asia ; it was first thoroughly explored fifteen 

 ye.rrs ago by a mission under Lagree and Garnier, which came 

 to the conclusion that this magnificent water-way was useless 

 for trade purposes on account of its rapids. 



Lieut. Allem has lately returned to San Francisco from a 

 successful exploration of Ala>ka, undertaken by direction of the 

 United .States Government. He left Sitka in February, going 

 to the mouth of the Copper River, which he ascended as far as 

 the great mountain range of Alaska. He crossed the mountains 

 with snow-shoes, coming to the sources of the Tennah, which 

 river he followed for 800 miles to its junction with the Takon, 

 and he descended this latter river to its mouth, a journey of 

 between 400 and 500 miles. From the mouth of the Takon he 

 went to Fort Michael, on Behring's Straits, whence he came 

 home. 



The proposal that the Netherlands Govern.neiit should make 

 a grant to the Dutch Geographical Society towards the expenses 

 of the projected scientific expeditiin for the exploration of the 

 half of New Guinea belonging to Holland has been rejected by 

 the Second Chamber by a large majority, there being forty-nine 

 votes against the motion to twenty-one in favour of it. In the 

 debate most of the speakers expressed their conviction of the 

 desirability of the expedition maintaining the character of a 

 purely private enterprise. 



A new edition of Dr. Hunter's " Indian Gazetteer of India " 

 in twelve volumes is in the press. Several of the volumes will 

 be published in the course of the next few weeks. 



The November number of the Austrian Mutatsschrift fur 

 den Orient contains a long communication from Dr. Lenz, from 

 Ango-Ango, with reference to his expedition to the Congo. It 

 deals mainly with the superficial aspects of the various settle- 



ments on the West Coast of Africa, of the trade there and its 

 future prospects, and especially with the prospects of Austrian 

 trade. 



Under the title, " La Coree avant les Traites," M. Jametel, 

 a French writer on the Far East, has published, in a hrochiire of 

 about eighty pages, four articles which he contributed to receut 

 numbers oi La Revue de Geographic. He describes the voyage from 

 Nagasaki to Fusan, a Corean port then only opened to Japanese 

 trade, and gives a sketch of the history of the peninsula from 

 early times ; finally he describes the Japanese settlement at 

 Fusan and the neighbouring Corean town of Toraifu, and adds 

 a few words about the Island of Quelpaest. The account is 

 very lively and amusing, but it can hardly be said to add much 

 to our geographical knowledge of Corea, small as that was 

 before the treaties. 



CHLOROPHYLL^ 



A LL who are accustomed to observe vegetation must have 

 been struck with the great variety of shades of green 

 which the foliage of difierent plants presents. Without pre- 

 tending to generalise further, it may be stated that, at any 

 rate so far as our common agricultural plants ai-e concerned, 

 they show somewhat characteristic shades of colour, according 

 to the Natural Order to which they belong — the Leguminosse 

 differing frooi the Gramine;-c, the Cruciferje, the Chenopodiacese, 

 and so on. But the same description of plant will exhibit very 

 characteristic differences, not only at different stages of growth, 

 but at the same stage in different conditions of luxuriance, as 

 aflfected by the external conditions of soil, season, manuring, 

 &c., but especially under the influence of different conditions as 

 to manuring. 



The Rothamsted field experiments have afforded ample op- 

 portunity for observations of this kind ; and it has been quite 

 evident that, in a series of comparable experiments with the 

 same crop, depth of green colour by no means necessarily im- 

 plied a finally greater amount of carbon assimilation ; whilst we 

 have long ago experimentally proved that the deeper colour was 

 associated with relatively high percentage of nitrogen in the dry 

 or solid substance of the herbage ; and this obviously means a 

 lower relation of carbon to nitrogen. 



Mentioning these facts to Dr. W. J . Russell, who has devoted 

 so much attention to the subject of chlorophyll, he kindly under- 

 took to make comparative determinations of the amounts of 

 chlorophyll in parallel specimens, in which we were to deter- 

 mine the per-centages of dry matter and of nitrogen. Accord- 

 ingly in June, 1882, during the period of active vegation, Ur. 

 Russell spent a day at Rotharrrsted for the purpose of collecting 

 appropriate samples, which were taken from several differently- 

 manured Idiots of meadow-grass, wheat, barley, and potatoes, 

 respectively. 



The following table gives the results of some of these experi- 

 ments ; namely, the percentages of nitrogen, and the relative 

 amounts of chlorophyll, in the separated gramineous and the 

 separated leguminous plants in the mixed herbage of grass-land ; 

 in specimens of wheat grown by a ]Durely nitr'ogenous manure, 

 and by the same nitrogenous manure with a full mineral manure 

 in addition ; and in specimens of barley grown by a purely nitro- 

 genous manure, and by a mixture of the same nitrogenous 

 manure and mineral manure in addition. It is to be borne in 

 mind that the specimens were collected while the plants were 

 still quite green and actively growing. It should be further 

 explained that the amounts of chlorophyll recorded are, as stated 

 in the table, relative and not actual ; that is to say, the figures 

 show the relative amounts for the individual members of each 

 pair of experiments, and not the comparative amounts as 

 between one set of experiments and another. 



It will be seen in the first place that the separated leguminous 

 herbage of hay contained a much higher percentage of nitrogen 

 in its dry substance than the separated gramineous herbage ; and 

 that, with the much Irigher percentage of nitrogen in the legu- 

 minous herbage, ther-e was also a much higher proportion of 

 chlorophyll. Under comparable conditions, however, the 

 Leguminosx eventually maintain a much higher relation of 

 nitrogen to carbon than the Gramineae ; in otlier words, in their 



^ " Note on some Conditions of the Development, and of tfie Activity, of 

 Cliloi-opliyll." By Prof. J. H. Gilbert, LL.D., F.R.S. Read in Section B 

 at the me^tins of the British Association at Aberdeen, September, 1SS5. 

 (Abstract.) 



