io6 



NATURE 



[June 14, 19 17 



history; I trust that the pleasure of 5'our pursuits 

 affords you some reward for your exertions. Some 

 time since you were so kind as to send me through 

 Mr. E. Lumb some most curious, and to me most 

 valuable, information regarding the Niata oxen. I 

 should be deeply' obliged by any further facts about 

 any of the dom.estic animals of La Plata ; on the origin 

 of any "breed" of poultry, pigs, dogs, cattle, etc. I 

 should be much interested by a brief description of the 

 habits and appearance of the pigs, dogs, etc., which 

 have run wild, and especially on the habits of these 

 wild breeds, when their young are caught and reared. 

 Will a puppy of one of the run-wild dogs, if brought 

 up carefully, be as tame as a common dog? Any 

 information on all such points would be of real service 

 to me; and my address, should you find time to write 

 to me, will always be that at the head of this letter. 

 I most sincerely wish you all success in your admirable 

 labours, and if at any time I can be of any service, I 

 shall be happy to be so; but I am sorry to say I am 

 not connected with any mercantile establishment and 

 cannot recommend agents, etc., etc. 



With much respect, I beg to remain, Sir, 



Your obliged and obedient servant, 



Charles Darwin. 



P.S. — I omitted to state that Prof. Owen has heard 

 that a collection of bones from Buenos Aires some 

 time since arrived at Paris. 



Plated Teeth of Sheep. 



Plating of the teeth of sheep with '"gold" can 

 scarcely have been a common phenomenon, in Scot- 

 land at any rate, for in the few cases mentioned by 

 the older writers it is recorded as something of a 

 marvel. 



In 1536 Hector Boece, Bishop of Aberdeen, thus 

 described the sheep of Doundore (Bellenden's trans- 

 lation) : — "In Gareoth [Garioch, a district of central 

 Aberdeenshire] is ane hill namit Doundore, that is 

 to say, the Goldin Montane. The scheip.that gangis 

 on this montane ar yallo; thair teeth are hewit like 

 gold ; thair flesche reid, as it wer littit with safron ; 

 thair woll is on the same maner." This locality 

 remained for a couple of hundred years the typical Scot- 

 tish locality, if one may so call it, for golden-toothed 

 sheep, foi^ it is mentioned by many writers, whose 

 accounts vary mainly in the spelling of the hill-name 

 — Dundore, Dunedere, Dinnedure, etc. It is the 

 prominent conical, ruin-capped hill, still known as 

 Dunnideer, near the railway station of Insch, in 

 central Aberdeenshire. 



Martin, in his " Description of the Western Islands 

 of Scotland" (1703), almost suggests that the colour- 

 ing of the teeth in the Outer Hebrides is due to 

 native gold in the soil: — "The Natives affirm that 

 Gold Dust has been found at Griminis on the Western 

 Coast of the Isle of North Uist, and at Copveaul in 

 Harries; in which, as in other parts of the Isles, the 

 teeth of the Sheep which feed there are died yellow." 



In these cases it is likely that iron in fair quantity 

 was present in solution in the bogs and streams, for 

 Dunnideer is formed of a cap of coarsely grained 

 syenite lying upon the basic intrusive mass of the 

 district, which possesses a moderate ferro-magnesian 

 content, while the peat-bogs characteristic of the Outer 

 Hebrides rest upon Lewesian gneiss, the ferruginous 

 tendency of which in the area is indicated by the 

 presence of patches of hornblende and garnet. In 

 the Aberdeenshire area, iron pyrites, also, is dissem- 

 inated throughout the intrusive mass in 'microscopic 

 crystals. James Ritchie. 



Edinburgh, Tune 7. 



NO. 2485, VOL. 99] 



The Organisation of Scientific Literature. 



In the current number (June, 1917) of Scientia 

 (pp. 530-32) there is a somewhat full account of dis- 

 cussions that took place at the meeting of the Italian 

 Society for the Advancement of Sciences at Milan in 

 April last, which are of great interest to us, particu- 

 larly at the present time. Prof. Gino Loria spoke 

 about national and international collaboration in pub- 

 lications 'on science and culture, and Prof. Eugenio 

 Rignano spoke on projected scientific periodicals of 

 the Entente. The praiseworthy scheme of Prof. 

 Rignano was fully described by him in a 

 letter printed in Nature of January 25 of 

 this year, and I may also refer here to an article by 

 myself on the organisation of scientific literature in 

 Science Progress for last April. It is necessary that 

 the nations of the Entente should take immediate 

 steps to make themselves less dependent on Germany 

 for the results of organisation of scientific and philo- 

 sophical literature, if for no other reason than that 

 Germany's powers of production are very much 

 lessened at present, and probably will be even more 

 so in future. Science is, of course, not an affair 

 merely of particular nations or groups of nations ; all 

 nations should combine to make the work of advance 

 in science rather easier by organising its literary aids. 

 It seems that we, in particular of all nations, ought 

 not to remain content with the position into which we 

 have fallen in this possibly humble organising duty of 

 science. I may remark that I have been in corre- 

 spondence with the Government with respect to plans 

 for Government action in this direction, and that, 

 though some outcome of the correspondence does not 

 seem impossible, it is to be feared that the curse of 

 delay will act as a clog on the wheels of progress- 

 One would have thought that by now the evils of 

 inefficiency, slackness, and neglect of science had been 

 sufficiently forced upon us. In France, Italy, and 

 America there have been public expressions of a wish 

 to help in this need for the organisation of the litera- 

 ture of scientific research. 



Philip E. B. Jourdain. 



The Bourne. Basingbourne Road, 

 Fleet, Hants, June 2. 



The Origin of Flint. 



Sir E. Ray Lankester (Nature, June 7, p. 283) 

 attributes the black colour of flint to carbon, but has 

 he considered whether ferrosoferric oxide may be the 

 cause of the colour? 



I have recently observed a similar, almost black 

 colour in specimens of hydrated, colloidal sodium sili- 

 cate, which contained small quantities of oxide of 

 iron, originally in the ferrous state, but partly 

 oxidised. 



It has been pointed out by Hofmann and Resen- 

 scheck (Annalen, 1905, vol. cccxlii., p. 364) that depth 

 of colour in various chemical compounds is connected 

 with the presence within the same molecule of atoms 

 of an element exercising two different valencies. The 

 deep colours of sulphur sesquioxide and uranouranic 

 oxide are examples of this phenomenon, and especially 

 the deep blue colour of ferric ferrocyanide. The dark 

 colour of hydrated, ferrosoferric oxide is well seen when 

 white, ferrous hydroxide, precipitated by alkali from 

 ferrous sulphate solution, undergoes atmospheric oxida- 

 tion, or when a mixed solution of ferrous and ferric 

 salts is similarly precipitated. The greenish-black 

 colour, which cannot possibly be due to a mixture of 

 white, ferrous hvdroxide and reddish-brown, ferric 

 hydroxide, is to be attributed to a compound of the 

 two hydrated oxides. R. M. Caven. 



University College, Nottingham, June 11. 



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