July 1 6, 18 74] 



NATURE 



205 



f Now I can assure Mr. Tylur, fi om liaving often conversed with 

 Dr. Martins on Brazilian topics, that liis degeneration theory be- 

 longed to his earlier life, that afterwards he altered his opinions, 

 and that the passage quoted by Mr. Tylorfrom Martins contained 

 his latest conviction. Soon after the publication of his Ethno- 

 graphy he died at Munich. Oscar Peschel 



*■ Dr. Martius found the rude natives of Brazil treating the 

 hunting-ground of each tribe as common to all the tribesmen, 

 but allowing each family to hold as its own freehold the ground 

 which it had built huts on, or brought under tillage. It is not 

 surprising that this ethnologist, comparing such a rudimentary 

 form of the " village community " with its more artificial ar- 

 rangements- in ancient Europe, should have considered the 

 Brazilian tribes to have arrived at an intermediate stage of the 

 development of land-laws, above that of the lowest savages, and 

 on the way to that of more civilised nations. Mr. Edkins, how- 

 ever, in his letter to NATURE,voi. x. p. i63,thinksthat Dr. Martius 

 should not have explained the origin of the Brazilian land-law in 

 tills obvious way. The suggestion which he offers in its place is, 

 that inasmuch as the Chinese had in old times a highly artificial 

 system of partitioning their village-lands among the heads of 

 families, some of these Chinese are to be supposed to have 

 emigrated to the Brazilian forests and introduced this system, 

 which in course of ages decayed till nothing was left but the 

 simple rule found by Dr. Martius. But is not the word "far- 

 fetched " applicable to this argument ? Sooner than allow the 

 rude people of Brazil to have been human beings capable of 

 adopting the simplest social regulation for their own evident 

 benefit, Mr. Edkins sends half-way round the world for iniagui- 

 ary Chinese emigrants, to introduce, not the savage law itself, 

 but a civilised law which, if broken down to its last remnant, 

 might be reduced to the Brazilian level. And, one may go on 

 10 ask, where is it likely that the Chinese themselves got their 

 law of village-lands, if it was not developed out of lower stages 

 of the law of property, belonging to lower stages of civilisation ? 

 If Mr. Edkins \\ould turn his great knowledge of Chinese 

 matters to investigating the origin of Chinese institutions, I think 

 he would contribute new evidence to the development-theory 

 of culture. Mr. Edkins next brings forward the evidence of 

 numerals in Polynesia as proof of degeneracy in civilisation. 

 The fact that the word /«<;«!) means 10,000 in the Tonga Islands, 

 4,000 in the Sandwich Islands, and 1,000 in New Zealand, he 

 accounts for on the supposition that the highest number was 

 the original meaning, but that it was lowered with a fall in 

 civilisation. But he will, I think, on further examination be 

 satisfied that the real reason has nothing to do with degeneration, 

 but with the curious Polynesian habit of counting by twos, fours, 

 and even tens. Thus ran and mano, which in New Zealand 

 mean 100 and 1,000, come to mean in Hawaii so many fours, 

 viz. 400 and 4,000; Mr. Edkins' own example from Ponape 

 .shows the same done with tens (see Hale's "Ethnography of 

 Wilkes' Expedition "). Mr. Edkins also remarks that "the 

 Polynesians formerly had a decimal arithmetic ; now it has sunk 

 in Australia to quaternary or quinary arithmetic." But the 

 Australians are not of the same race as the Polynesians, nor is 

 there the least reason to suppose that they were ever at a 

 Polynesian level of culture. As the evidence of numerals has 

 been introduced, it may be mentioned that both Australians and 

 Polynesians use numerals derived from counting on the fingers. 

 Thus the Polynesian lima, i.e. "hand," is the ordinary numeral 

 for five, while the West Australian will say "the hand on either 

 tide and half the feet," meaning by this long expression the 

 number I5(seemy " Primitive Cultuie," chap. 7). Imayaddthat 

 I have been trying for years to get any degenerationist to answer 

 the argument from numerals of this very common class, which 

 can only have arisen by development from the lower stage of 

 counting on the fingers, and which therefore ])rove savage tribes 

 to be capable of independent intellectual development. 



The Quarterly Rniiao argument from the recent discoveries of 

 Dr. Schliemann in the ruins he considers to be of Troy, merely 

 shows that low barbarians may build on the ruins of towns 

 previously inhabited by more civilised nations. This often 

 happens, and can hardly be held to prove that the higher civilisa- 

 tion existed in the world before the lower. 



As to the observations (vol. x. p. 163) of Mr. Hyde Clarke on 

 affinities which he believes to exist between languages of Brazil 

 and of the Old World, I cannot make any answer, not having 

 seen any comparative vocabularies on which such an opinion 

 could be founded. 



Edward B. Tylor 



Photographic Irradiation 



For the purpose of determining whether any sensible amount 

 of the photographic irradiation surrounding the image of a bright 

 object could be traced to an action taking place within the thick- 

 ness of the collodion film, I some time ago tried an experiment in 

 many respects similar to that detailed by Mr. Aitken in your last 

 number (vol. x.p. 185), A piece of cardboard with four parallel nar- 

 rowopenings, each some I2in. long, was hung against the glass roof 

 of a photographic studio so as to be projected ag.iinst the back- 

 ground of a bright sky. One of the slits or openings was covered 

 with a piece of red glass, another was glazed with blue glass, the 

 third was left entirely uncovereil, and the fourth was covered by 

 a piece of thin tracing paper. The slits in the cardboard screen 

 were carefully focused, and over-exposed photographs were taken 

 with a camera in which no s'ops were used. Upon the collodion 

 film and immediately in contact with it was laid a piece of plati- 

 num foil quite thick enough to be perfectly opaque. The camera 

 was so placed that the images of the slits fell partly upon the 

 platinum foil and partly upon the collodion film. 1 have now 

 before me two of the platis, each taken with an exposure of five 

 minutes. The first was coated in the ordinary manner with a 

 single collodion film, but the other was coated three times suc- 

 cessively with collodion, so that the film was rendered very 

 thick ; but the eating in or encroachment of the photo- 

 graphic images of the slits under the platinum foil is 

 hardly perceptible in either plate ; indeed, I feel that I 

 cannot say with certainty whether there is any encroachnnent of 

 the image proper, though there are very marked brush-like 

 extensions from the ends of the images, as well as a cloudy semi- 

 circular field symmetrical with the end of each image, evidently 

 arising (rom reflections from the back of the plate. At first 

 sight the brush-like semi-opaque extensions miijht be taken for 

 the ordinary photographic irradiation eating under the platinum 

 foil ; but on more closely examining the ends of tire images, the 

 hazy opacity is seen to extend farther in some directions than in 

 otheis, and to be broki n up in soaie cases into five or six little 

 streams or brushes. The decrease in the opacity of the brushes 

 is aUo less uniform than the de.ria:o in the opacity of the ordi- 

 nary irradiation bon'er. The brushes extend to a distance of 

 abcut '02 in. under the edge of the platinum foil. 



I do not at present s-^e my way to devise an experiment which 

 would determine what is the cause uf these little brushes, nor 

 have I at present had an opportunity of repeating a similar ex- 

 periment with the dry-plate process ; but the biushes have the 

 appearance to me of having been produced by streams in the 

 delicate film of liquid which must extend under the platinum, 

 s'reams which probably carry with them little masses of light- 

 altered silver, that are soon deposited or strained out in the 

 spongy tissue of the colloJion. 



If the spreading action under the platinum foil were caused 

 by liijht dispersed within the thickness of the collodion, one 

 would expect such action to take place symmetrically around the 

 place where the bright image is cut off instead of being broken 

 up, as I have described, into bundles or brushes. On the other 

 hand, slight differences in the texture of the collodion, or minute 

 inequalities on the edge of the platinum foil, might cause the 

 streams in the liquid film to move more easily at one point than 

 at another. 



I should be glad to be informed what was the distance of the 

 opaque bar from the collodion plate in Mr. Aitken's experi- 

 ments, and whether there is not any photo';raphic trace of de- 

 fraction bands, owing to the bar not having been in focus ; 

 possibly the presence of these may account for the apparent 

 difference in our results. It will be seen that the experiment 

 which I have described points to the same conclusion as that 

 forme ly announced by Lord Lindsay and myself, viz. that the 

 inner photographic diffraction edge is chielly due to the imper- 

 fection of the instrument producing the image, chief among 

 which is to be counted the aberration of oblique pencils. 



A. CowpER Ranyard 



Mr. Aitken's observations on photographic irradiation in 

 Nat»re, vol. X. p. 185, are confirmed by many experiments I 

 have made. I spent a long time in efforts to get rid of irradiation 

 in bromide of silver films, oneof the results of which I stated in a 

 former note to Nature (vol. x. p. 63). There is the most striking 

 difl'erence in the behaviour of films containing iodide of silver 

 only to those containing the bromide alone, the latter, especially 

 when dry, giving much greater irradiation ; and the dift'erence is 

 again complicated by the addition of certain substances (notably 

 albumen) to the film in the course of preparation. As my experi- 



