92 



NA TURE 



[Nov. 26, 1885 



case carbon is not assimilated in so large a proportion to the 

 nitrogen taken up. 



Next, it is to be observed that tlie wheat plants manured 

 with ammonium-salts alone show a much higher percentage of 

 nitrogen than those manured with the same amount of ammo- 

 nium-salts but with mineral manure in addition. The high 

 proportion of chlorophyll again goes with the high nitrogen 

 percentage ; but the last column of tlie table shows that, with 

 the ammonium -salts without mineral manure, with the high 

 percentage of nitrogen, and the high proportion of chlorophyll, 

 in the dry substance of the green produce, there is eventually a 

 very much less assimilation of carbon. The result is exactly 

 similar in the case of barley ; the plants manured with ammo- 

 nium-salts alone showing the higher percentage of nitrogen, and 

 the higher proportion of chlorophyll, but eventually a much 

 lower assimilation of carbon. 



It is evident that the chlorophyll fonnation has a close con- 

 nection with the amount of nitrogen assimilated, but that the 

 carbon assimilation is not in proportion to the chlorophyll 

 formed, if there be a relative deficiency of the necessary mineral 

 constituents available. No doubt there has been as much, or 

 more, of both nitrogen assimilated and chlorophyll formed, over 

 a given area, where the mineral as well as the nitrogenous 

 manure had been applied, the lower proportion of both in the 

 dry matter being due to the greater assimilation of carbon, and 

 consequently greater formation of non-nitrogenous substances. 



It is of interest to observe that these results of experiments in 

 the field are perfectly consistent with those obtained by vegetable 

 physiologists in the laboratory ; they having found that the 

 presence of certain mineral or ash constituents, and especially 

 that of potassium, is essential for the assimilation of carbon, no 

 starch being formed in the grains of chlorophyll without the aid 

 of that substance. Sachs says: — "Potassium is as essential 

 for the assimilating activity of chlorophyll as iron for its 

 production." 



Relation hchueen Nil. 

 Formation, ai 



«en Accumulation, Chlorophyll 

 ' Carbon Assimilation. 

 epresent determinations in the not fully d 



CARTOGRAPHICAL WORK IN RUSSIA IN 

 1884 > 

 'T'HE chief surveys in European Russia are directed towards 

 -'- mapping South Finland, the western frontier on the Duna 

 and Dnieper, and the Government of Taurida. The surveys are 

 made on a scale of 1750 feet to the inch, and the inequalities of 

 soil are represented by horizontal lines received from accurate 

 levellings. Since 1S70 about 44,000 square miles have been thus 

 mapped, and, in 1884, 6850 square miles were added to the 

 above, the newly-annexed part of Bessarabia included. The 

 geodetical triangulation for this survey was continued in Poland 

 and Grodno. The work for an orographical map of Russia, 

 which must be based on accurate levellings, has been busily 

 continued since 18S1, as also telegraphic determinations of longi- 

 tudes in Poland. 



^ Izvestia of the Russian Geographical Society, September, 1885. 



Instead of the former map of West and Middle Russia, on 

 150 sheets, on the scale of 3 versts (2 miles) to an inch, the 

 Topographical Department is now preparing a new map on a 

 larger scale (2 versts to an inch), which will be printed on a 

 new method, by helio-engraving, with level-lines in a sepa- 

 rate colour. Many preliminary essays having been m.ade, this 

 method has been definitively adopted. The map of Russia (10 

 versts to an inch) has been completely revised by General 

 Strelbitzky ; and the map of the Caucasus, on the same scale, 

 was completed in 1884. The northern and north-eastern sheets 

 of the map of European Russia will be completely revised in 

 accordance with new surveys. 



The map of the Asiatic dominions of the Empire, with the 

 neighbouting regions (100 versts to an inch), is completed, and 

 is printed in colours. That of the eastern part of the Balkan 

 peninsula is prepared on two different scales (5 and 3 versts 

 to the inch), and on both maps the inequalities of the soil are 

 represented by horizontal lines. The middle parts, including the 

 Balkan ridge, were ready to print. Helio-engraving had also been 

 resorted to, but it required considerable retouching by the 

 engraver. 



Leaving aside the purely military maps of Middle Europe and 

 the statistical maps of the St. Petersburg military district, the fol- 

 lowing maps, published in 1884, are especially worthy of 

 notice : — The region of the Cossacks of the Ural (10 versts to 

 an inch) ; the Island of Sakhalin (40 versts) ; North- Western 

 Mongolia (50 versts), including all the rich materials collected 

 by the expeditions of MM. Potanin, Rafailoff, Orloff, Prjevalsky, 

 Pevtsoff, and several others ; Afghanistan (50 versts), accord- 

 ing to the surveys and information of JI. Lessar ; the south- 

 western Turkoman region, by the same (20 versts) ; the surveys 

 of M. Kosyakoff in Karategin and Darvaz (15 versts) ; the survey 

 from Staro-Tsurukhaitu to Aigim, on the Arnur (25 versts) ; a 

 map of China proper, by M. Matusovsky (100 versts) ; the plans 

 of Odessa, KikolaiefF, Ekaterinoslav, Bendery, and Elizabeth- 

 grad, as also of Plevna and Lovtcha ; the neighbourhoods of 

 Kazan and of Novogeorgievsk, and many others. 



On the Caucasus, as soon as the triangulation of the region 

 was terminated some fifteen years since, a series of surveys, on 

 scales of 1400, 1750, and 3500 feet to an inch, w-ere underlalcen. 

 Large parts of Transcaucasia were thus mapped. Since 1881 

 the work has been prosecuted in the central parts of the great 

 Caucasus ridge, in Daghestan, and in the Transcaspian region ; 

 about 30,000 square miles were thus surveyed. In 1884 the chief 

 surveys were made in the teritory of Merv, along the Murghab ; 

 and on the routes between Kizil-arvat, Petro-alexandrovsk, 

 Khiva, and Merv. The drawing and engraving of the great 

 map of the Caucasus with the neighbouring parts of Persia and 

 Turkey, as also of that of the Transcaspian region, both on a 

 scale of 5 versts to the inch, have been prosecuted. 



In Turkestan the chief attention has been directed towards 

 the survey of the former khanate of Kokan, now the province of 

 Ferghana, the work meeting with great difficulties owing to the 

 hilly character of the region and its unhealthy climate. Recon- 

 noitring has been prosecuted in the vassal khanates of Bokhara, 

 west of the Pamir, by a topographer who accompanied Dr. Regel. 



The mapping of the town of Tashkend, which covers as much 

 as thirty-five square miles, and where trigonometrical measure- 

 ments meet with great difficulties on account of refraction and 

 the want of wood for the triangulation-pyramids, a system 

 known under the name of PolygonaU Ziige, and which has been 

 greatly extended of late in Germany, has been resorted to. The 

 horizontal angles were measured by a little universal instruinent, 

 and the distances by a ribbon, with the help of the eclimetre. 

 The results obtained were very satisfactory. Several new sheets 

 of the 10 versts map were printed, as also a map of the neigh- 

 bourhood of Tashkend. 



In the Omsk military district, detailed surveys, based on a 

 geodetical net, have been prosecuted since 1S70 to the south- 

 west of the Irtish River, between its source; and Pavlodar. In 

 1883 and 1884 large spaces in the region between Omsk, 

 Pavlodar, Petropaulovsk, and Kokchetav were mapped, and a 

 series of latitudes and longitudes were determined. 



In Eastern Siberia the Government of Irkutsk is now surveyed 

 on a scale of one verst to the inch, the trigonometrical net 

 having been completed in 1S82. The upper parts of the Vition 

 and Barguzin were reconnoitred, and the trigonometrical net 

 extended in Southern Transbaikalia. On the Pacific coast, the 

 region east of the Suifun River, and on the Chinese frontier, has 

 been surveyed. 



