92 



NATURE 



[March 29, 191 7 



These niethcxls have previously been advocated in this 

 country, and are worthy of investigation, but the 

 obvious increased demand for labour as compared with 

 ordinary methods of cultivation must render them 

 largely impracticable for adoption under present condi- 

 tions. 



The Irhh Naturalist for March contains the annual 

 report of the Royal Zoological Society, from which it 

 is clear that the society has passed through a very 

 troublous year, and one which came dangerously near 

 to disaster. During the week of the Easter rebellion 

 the difficulty of conveying food for the larger carni- 

 vores to the gardens was so great that some of the 

 less valuable stock had to be sacrificed, including "an 

 old pony, a donkey, a goat, and a few dingoes." These 

 had to go to feed the lions and tigers. The keepers, 

 for the time, had to be housed in the gardens owing 

 to the danger of venturing into the streets of Dublin. 

 Further, owing to the social unrest, the receipts for 

 the month practically ceased. This loss, with the fall- 

 ing off of revenue owing to resignation of subscribers, 

 has seriously crippled the society, but, fortunately, 

 thanks to the generositj- of some of its members, the 

 deficit at the end of the year was much less than at 

 one time seemed inevitable. The 5'oung female 

 gorilla, we sire glad to notice, is not only still alive, but 

 is, further, in better health than was the case when the 

 report for 1915 was issued. During midsummer a 

 female bison calf was born and is still thriving. For 

 the first few weeks it was of a bright red colour, but 

 has now assumed the typical dark coat. 



The plans of a projected aerial expedition to New 

 Guinea "by Dr. Eric Mjoberg, of Stockholm, are out- 

 lined in the February issue of the Geographical 

 Review (vol. iii., No. 2). In view of the great diffi- 

 culties presented by climate and vegetation in reaching 

 the mountains of the interior, Dr. Mjoberg proposes 

 to use aeroplanes or even hydroplanes. He considers 

 that the interior v.ill afford four different possibilities 

 of landing: alpine meadows at 12,000-13,000 ft., open 

 or thin savannas at lower altitudes, steppes of alang 

 grass known to occur here and there, and lake surfaces. 

 These last are not certain to occur. A reconnaissance 

 is first to be made with a light machine. Then a 

 heavier machine capable of carrying five passengers 

 and stores is to leave the base for the interior. Sub- 

 sequent communication would be maintained between 

 the coast and the interior stations of the expedition in a 

 few hours' time. Dr. Mjoberg proposes to take with 

 him two surveyors, a botanist, a zoologist, and a 

 geologist, besides several expert airmen. 



The annual report of the Weather Bureau of the 

 Manila Observatory for 1915 has been published. It 

 contains the full hourly meteorological observations 

 made throughout the year. In addition to the central 

 observatory at Manila, the Weather Bureau maintained 

 fifty-six other stations throughout the Philippines, and 

 one at Yap, in the western Carolines. There seems, 

 however, to be some doubt whether the station at Yap 

 has been maintained in working order since the change 

 in ownership of the Carolines. The lack of communi- 

 cation with Yap interfered with the typhoon warnings 

 sent out by the Manila Observatory. The volume 

 directs attention to the fact that the Manila Observa- 

 tory has now been in existence for fifty years. 



Messrs. Kodak, Ltd., have just issued an illus- 

 trated booklet on " Kodak Bromide Pictures, by Some 

 who Make Them," a collection of seven articles, sup- 

 plemented by the firm's own instructions. Though 

 obviously of chief interest to those who use bromide 

 papers for pictorial purposes, there are suggestions 

 that may be of much wider utility, and the illustra- 

 NO. 2474, VOL. 99] 



tions show what a great range of possibilities is 

 offered by this method of printing. The scientific 

 worker will need, however, to add to these the results 

 obtainable on papers that have a glossy surface, 

 which emphasises feeble and minute details, and will 

 note the " transferotype " paper which permits of the 

 film that bears the image being transferred to sur- 

 faces such as those of glass, porcelain, wood, metal, 

 canvas, etc. 



Cert.'WN species of lichens have long been used by 

 the inhabitants of Ireland, Scotland, and other parts 

 of Northern Europe for dyeing wool various shades of 

 yellow or reddish-brown. Four of these lichens, Par- 

 nielia saxatilis, Ach., Ranialina scopulorum, Ach., 

 Ranudina cuspidata, Nyl., and Physcia parietina, De 

 Not., have been examined by Dr. Hugh Ryan and Mr. 

 W, M. O'Riordan (Proceedings of the Royal Irish 

 Academy, 19 17, xxiii., Section B, pp. 91-104) with 

 the view of isolating their tinctorial constituents. The 

 first three lichens were submitted to a preliminary 

 extraction with ether. By this means a colourless, 

 crystalline substance was obtained from Parmclia 

 saxatilis, probably identical with Zopf's stereocaulic 

 acid, whilst Ramalina scopulorum and R. cuspidata 

 gave Zopf's rf-usnic acid. After the treatment with ether 

 the three lichens were extracted with boiling acetone. 

 By this means a colourless, crystalline substance, ap- 

 parently identical with Zopf's salazinic acid, was 

 obtained from Parmelia saxatilis. The lichen Ratna- 

 lina scopulorum gave a white, microcrystalline sub- 

 stance probably identical with Zopf's scopuloric acid, 

 whilst R. cuspidata also yielded a white, crystalline 

 substance, which, however, was not identified with any 

 known compound. That these three substances are 

 the tinctorial constituents of the respective lichens is 

 shown by the fact that when wool is boiled with water 

 containing them it is dyed in a manner similar to that 

 produced by the lichens. Physcia parietina when ex- 

 tracted with chloroform gave a quantity of physcione 

 (probably identical with frangula-emodin-monomethyi- 

 ether), which has little or no dyeing properties, but 

 which when demethjiated gives frangula-emodin. The 

 latter dyes unmordanted wool a dull orange-y'tellow 

 colour. 



A USEFUL catalogue (No. 67, March) of books of 

 science (many of them scarce) has been issued by 

 Messrs. Dulau and Co., Ltd., Soho Square, W.i, 

 which should appeal to many of our readers. It is 

 arranged conveniently under the headings Botany and 

 Horticulture. Geology and Palaeontology, Entomology 

 (with subdivisions). Ichthyology, Mammalia, Mollusca 

 and ConchologA-, Ornitholop-v, Reptilia and Batrachia, 

 and Scientific Voyages and Greneral Zoology. 



OUR ASTRONOMICAL COLUMN. 



The Spectrum of N.G.C. 7023. — Dr. Max Wolf has 

 previously pointed out that many nebulae in the Milky 

 Way are encircled by a nearly circular space which 

 is void of faint stars, and that this lacuna is usually 

 situated at the end of a long, starless channel. Such 

 nebulae are designated " Hohlennebel," or "cave- 

 nebulae," and Dr. Wolf has recently given an account 

 of spectroscopic observations of some of them which 

 have been made at Heidelberg {Ast. A'^ac/i., No. 4875). 

 One of the finest examples is H. iv. 74 Cephei (N.G.C. 

 7023), in which the cave has a diameter of nearly half 

 a degree, and the nebula surrounds the star B.D.4- 

 67° 1283, of magnitude 6-8. The photographs show 

 that the star is of type A, and that the spectrum of 

 the nebula exactly resembles it, without showing any 

 trace of the lines characteristic of gaseous nebulae. It 



