330 



NATURE 



[January 4, 1Q12 



■creen bring n-quirfd to khut the blue port of the purple 



out ! ' NVi this l.ns >jiv«'<» |inrti(-utnrly sharp hnn^i-o, and 



\i a very stronj;; fl- -<.Iv(<r. Now, however, Hcrr 



Winkel has revivrd : m red rorrertion* with Jena 



(jlassen. The result m, for briiihter, *har|)er, or, 



for their apertures, nirungi-r resolvinj* object-glass«'H will 

 not be found. This red correction is peculiarly suitable, 

 l)»cause a peacock-green glass screen turns red into black, 

 ;ind so makes a strongly contrasted image. When the 

 Podtira was first examinfd with the i '7 of 085 N.A., for 

 the moment it was difficult to exclude the idea that one 

 of the American red objectives was not on the nose-piece." 



The outstanding colour in the fluorite objectives is of 

 the same red tint. In these, of course, the outstanding 

 < otour is less, and their definition leaves nothing to be 

 desired. 



" Complanat " is a new word coined by Winkel for a 

 II -w set of Huyghenian eye-pioces which are strictly 

 achromatic and have a perfectly flat field. 



Messrs. Angus have also sent us Winkel's new form of 

 screw micrometer. This is based on a suggestion of 

 Koch's. A combination of scale and screw replaces the 

 combination of screw and thread, giving a ready means of 

 obtaining the exact measurement of objects subtending a 

 number of divi>ions of the scalp, the fractional part only 

 of an interval having to be determined by means of the 

 screw. In the instrument real or lateral displacement .is 

 measured to 1/500 mm., one turn of the screw travelling 

 over two divisions of the scale, an arrangement which we 

 think will be found inconvenient. 



The microscope stand is a beautifully finished specimen 

 of the Continental model ; an extension of the horseshoe 

 backwards would make it more stable. The gr.aduation of 

 the scales in the attachable mechanical stage, and its 

 general finish, leave nothing to be desired : the old reputa- 

 tion of the firm for fine metalwork is still kept up. 



We have also received from Messrs. Angus a microscope 

 and objectives representing the latest productions of tho 

 eminent firm of Reichert, of \'ienna. together with a 

 catalogue. As was to be expected, both the optical and 

 mechanical parts are of the highest excellence. In the 

 catalogue the number of fluorite lenses employed in each 

 apochromatic objective is stated. The apochromatic of 

 N.A. 1-30 sent us is a magnificent lens with little trace of 

 colour, and its definition does not break down under a 

 power of 3000. 



THE FLORA OF FORMOSA. 



PREVIOUS to the acquisition of Formosa by Japan, in 

 1895, little was known of the vegetation of the 

 mountains of the interior. Many European collectors had 

 visited the island, but none had been able to penetrate the 

 central range, en account of the hostility of the natives. 

 The Japanese soon organised a Botanical Survey, and 

 several botanists have been engaged in the investigation of 

 the flora, the results of their labours having been pub- 

 lished from time to time, mostly in English, with Latin 

 descriptions of the novelties, and figures of some of the 

 most remarkable plants. The forerunner was the 



Enumeratio Plantarum Formosanarum," bv J. Matsu- 

 mura and B. Hayata, which appeared in iqo6. This was 

 followed in IQ08 by Hayata 's " Flora Montana For- 

 mos;B "; and the same author has now issued a bulky and 

 important supplement.^ As is stated on the title-page. 

 Dr. Hayata worked out his collections at Kew, where he 

 had the opportunity of studying numerous types of genera 

 and species of Eastern plants first described bv the Kew 

 botanists. 



This work and its predecessors are mainly statistical, 

 descriptive, and pictorial, though publications on the 

 economic botany of the island are not wanting. However, 

 it is possible to extract much that is interesting in the 

 composition of the flora. Taking Dr. Hayata's own 



J A delicate test for colour is the raphae of a CheiT>-fieId Rhomboides, 

 when mounted in balsam, quinidine. or styrax. 



- Matrrials for a Flora of Formosa. Supplementary Notes to the 

 tnumeratio Plantarum Formosanarum and Flora Monta'a Formosa, based 

 on a btudy of the Collections of the Botanical Surveys of the Government 

 ot tormosa, pnncipally made at the Herbarium of the Roval Gardens. Kew. 

 journal of the College of Science, Imperial University of Tok\-o, vol. xxx.. 

 1911, pp. 47t. ' ' ' 



NO. 2201, VOL. 88] 



figure*, the " Enumeratio" compriact 1909 fip«ci<- 

 ing to 701 gcnfra and 153 families; and the pr- 

 plement brings ih»? numbers up to 3660, 83^> ^" 

 spectlvely. It should U- i-xplainr-d that tht-s' 

 to the flowering plant»> and ferns and th<>ir .1 I 



nearly all its features and generic elements die tlora at 

 Formosa is essentially Chinese, with a very large number 

 of pfHuliar specii^i. In all probability the numl>er of 

 species existing is far from exhaustwl ; but the v»-ry ••mall 



generic ♦•nd<'mi' ' " is not likely to be much •■ ■ •• ' 



by future < \: Excluding ferns, Fo 



Hemsley's " I '•<>n of Chinese Plants" 



representatives uf 159 families, so that there are n--.': .•■ 

 as many in the smaller area as in the large. The sitm- 

 fact comes out in comparing a county flora with that of 

 the whole of England, for example. .Although the moun- 

 tains rise to upwards of 13,000 feet, there is no real alpin>- 

 flora in Formosa, though many genera are represented 

 that are common to temperate and alpine zones. 



Of the Cupuliferae, the genera Fagus, AInus, Carpinus. 

 Castanea, Castanopsis, and Quercus are represented, the 

 last-named by thirty-two species. Salix is represented by 

 several species ; Populus absent. About five and twenty 

 Conifer* are recorded, including Chamaecyparis formos- 

 ensis, Cunninghamia Konishii, Jtiniperus morrisonicola, 

 J. formosana, Picea morrisonicola, Pinus formosana, P. 

 taiwanensis, Tsuga formosana, and Taiwania crypio- 

 merioides, all of which are supposed to be peculiar to the 

 island. The last is a monotypic genus endemic in 

 Formosa. Nepenthes is not known to occur, nor Pedicu- 

 laris, whereas in China there are about 150 species of ih 

 latter. 



\"ascular cryptogams are evidentiv strongly reprpsent«-<l. ;in 

 already there are on record upwards of 300 species of ferns, 

 about twelve species each of Lycopodium and Selaginella, 

 and two species of Equisetum. Orchids number about 

 sixty species, mostly small-flowered and inconspicuous. 

 The foregoing totals are partly compiled from Takiya 

 Kawakami's " A List of Plants of Formosa," published in 

 19 10. W. BorriNG Hemsley. 



THE INDIAN SALTPETRE INDUSTRY.* 



'T'HE production of potassium nitrate in India is probably 

 a very ancient industry, and at the present time, in 

 spite of German competition, the export still amounts to 

 about 20,000 tons per annum. As is well known, the 

 potassium nitrate is extracted by natives from soil collected 

 in the villages, where in all probability it has been formed 

 by bacterial decomposition of the organic matter, with 

 production first of ammonia and subsequently of nitrates. 

 The chemical and bacteriological changes have not yet been 

 studied, but the actual methods of extraction have recently 

 been described by Dr. Leather and Mr. Mukerji in a well- 

 illustrated bulletin issued by the Pusa Research .Station. 



The soil from which the crude saltpetre is extracted 

 usually contains about 3 to 5 per cent, of pure potassium 

 nitrate, although there may be as little as i per cent, or as 

 much as 29 per cent. ; chlorides and sulphates are invariably 

 present as well. The soil is scraped together in small 

 quantities and collected by a very low caste called 

 " Nuniah " or " Lunia," who also carry out the extraction 

 process. .\n earthen chamber, called the " Kuria " or 

 " Kothi," is first made of wet mud and then allowed to 

 dry ; the floor of this slopes somewhat from back to 

 front, where a hole is made at the lowest point for the 

 escape of the nitrate liquor. Raised a few inches above the 

 floor, and supported by a few loose bricks, is a false bottom 

 made of bamboos and matting, on which the saltpetre earth 

 is laid with the greatest care and so trodden in that no 

 crevices shall exist. As a rule wood ashes are mixed with 

 the earth beforehand. The filling-in process is stopped 

 when the layer of soil is about 6 to 8 inches in thickness; 

 a small piece of matting is then laid on the top, and water 

 is poured in until about one inch lies on the surface of the 

 soil. Several hours elapse before the water has percolated 

 and begun to flow out from the hole. It usually emerges as 

 a fairly concentrated clear solution, coloured brown by 



m' "The Indian Saltpetre Industry." By I. W. Leather and Jatindra 

 Nath Mulcerji. Agricultural Research Institute, Pusa. Bulletin No. i«, 

 1911. 



