204 



NATURE 



\Jan. i, 1880 



of the "manufactured diamond," since it differed in 

 some respects from the specimens I have since received 

 direct from Mr. Mactear. 



The diamond excels all substances in hardness. Its 

 crystals belong to the cubic system, and should no;, 

 therefore, present the property of doubly refracting light. 

 Frequently, however, from the influence of strains within 

 the crystal due to inclosed gas bubbles, or other causes, 

 diamonds are not entirely without action on a ray 

 of polarised light sent through them. Finally, the 

 diamond is pure carbon, and, as such, burns entirely away 

 when heated to a sufficiently high temperature in the air, 

 and more vividly so burns, or rather glows away, when 

 heated in oxygen gas. 



The specimens I had to experiment upon were too 

 light to possess appreciable weight, too small even to see 

 unless by very good eyesight or with a lens, yet were, 

 nevertheless, sufficiently large to answer the three 

 questions suggested bv the above properties. 



A few grains of the dust, for such the substance must 

 be termed, were placed between a plate of topaz— a 

 cleavage-face with its fine natural polish — and a polished 

 surface of sapphire, and the two surfaces were carefully 

 " worked " over each other with a view to the production 

 of lines of abrasion from the particles between them. 

 There was no abrasion. Ultimately the particles became 

 bruised into a powder but without scratching even the 

 topaz. They are not diamond. 



Secondly, some particles more crystalline in appearance 

 than the rest were mounted on a glass microscope slide 

 and examined in the microscope with polarised light. 

 They acted each and all powerfully in the manner of a 

 birefringent crystal. It seemed even in one or two of 

 them that when they lay on their broadest surface (it can 

 scarcely be called a " crystal-face") a principal section of 

 the crystal was just 'slightly inclined to a flattish side of 

 it in a manner that suggested its not being a crystal of 

 any of the orthosymmetrical systems. Be that as it may, 

 it is not a diamond. 



Finally, I took two of these microscopic particles and 

 exposed them to the intense heat of a table blow-pipe on 

 a bit of platinum foil. They resisted this attempt to 

 burn them. Then, for comparison, they were placed in 

 contact with two little particles of diamond dust exceeding 

 them in size, and the experiment was repeated. The 

 result was that the diamond particles glowed and disap- 

 peared, while the little particle from Glasgow was as 

 obstinate and as unacted on as before. I had previously 

 treated the specimen I have alluded to as the first on 

 which I experimented by making a similar attempt in a 

 hard glass tube in a stream of oxygen, and the result was 

 the same. Hence I conclude that the substance supposed to 

 be artificially formed diamond is not diamond and is not 

 carbon, and I feel as confident in the results thus obtained 

 from a few infinitesimal particles that can barely be mea- 

 sured and could only be weighed by an assay balance of 

 the most refined delicacy, as if the experiments had been 

 performed on crystals of appreciable size. 



Not content with merely proving what these crystalline 

 particles are not, I made an experiment to determine 

 something about what they are. 



Heated on platinum foil several times with ammonium 

 fluoride, they became visibly more minute, and a slight 

 reddish white incrustation was seen on the foil. At the 

 suggestion of Dr. Flight, assistant in this department, a 

 master in the craft of the chemical analyst, these little 

 particles were left for the night in hydrofluoric acid in a 

 platinum capsule. This morning they have disappeared, 

 having become dissolved in the acid. 



I have, therefore, no hesitation in declaring Mr. 

 Mactear's "diamonds" not only not to be diamonds at 

 all, but to consist of some crystallised silicate, possibly 

 one resembling an augite, though it would be very rash to 

 assert anything beyond the fact that they consist of a 



compound of silica, and possibly of more than one such 

 compound. 



The problem of the permutation of carbon from its 

 ordinary opaque black condition into that in which it 

 occurs in nature, as the limpid crystal of diamond is still 

 unsolved. That it will be solved no scientific mind can 

 doubt, though the conditions necessary may prove to be 

 very difficult to fulfil. It is possible that carbon, like 

 metallic arsenic, passes directly into the condition of 

 vapour from that of a solid, and that the condition for its 

 sublimation in the form of crystals, or its cooling into 

 crystal diamond from the liquid state, is one involving a 

 combination of high temperature and high pressure 

 present in the depths of the earth's crust, but very 

 difficult to establish in a laboratory experiment. 



Nevil Story-Maskelyne 



FURTHER NOTES UPON THE PAPUANS OF 



MAC LAY COAST, NEW GUINEA 



I. 



HAVING recently received from my friend M. von 

 Miklucho Maclay, by way of Singapore, some fur- 

 ther notes upon the ethnology of the Papuans of Maclay 

 Coast, in New Guinea, I herewith contribute the follow- 

 ing abstract of them to the pages of Nature, as the 

 periodical in which they were published is not readily 

 accessible to English readers. 1 



The Daily Life of /he Papuans.— With regard to the 

 application of pigment to the face and body, the Papuans 

 paint the face with red and black colours, the red being 

 such usually used by the young (those from fifteen to 

 thirty years "malassi "), and the black by those of riper 

 years. The young further use the colouring agents in 

 the form of various devices. On ordinary days they are 

 unpainted, or confine themselves to a ring round the 

 eyes or a line along the nose, which goes to join another 

 running from the temple to the vertex, over the shaved 

 eyebrows. On formal occasions, however, the whole face 

 is smeared with a pigment over which white and black 

 are drawn. Sometimes half of the face is painted black, 

 while the other half is red, which gives a very remarkable 

 appearance. The Tamo, or men over thirty years old, 

 almost never employ the real colour, but substitute black 

 instead. On important occasions the whole head is 

 covered with the pigment ; in fact, in certain districts, 

 e.g , " Kar Kar," Dampier Island, where this is abun- 

 dant, the inhabitants smear the whole body with it, and 

 with such care that it would be readily taken for their 

 natural colour. 



The women of Maclay coast are seldom to be seen 

 painted, and, when they are, in not so elaborate a mode 

 as are the men. A description has been already given of 

 the coiffure. Before the arrival of Maclay bamboo knives 

 and fragments of flint were used for the removal of the 

 hair ; but during his stay sherds of glass collected in the 

 neighbourhood of his hut were substituted. Another 

 method was also employed for the removal of single hairs 

 by means of a noose made with a stalk of grass, in 

 which the hair was twisted out of its follicle. Although 

 this operation would seem to be a painful one, a Papuan 

 has been seen engaged for three or four hours on this 

 occupation, without a shade of an expression of pain 

 being seen to pass over his features. Although the 

 Papuans of this region are not conversant with the art of 

 tattooing, they are accustomed to burn rows of scars in 

 lines upon the skin. The operation is thus performed: — 

 The patient having been placed either upon his back 

 or belly, a red-hot fragment of dry bark is laid 



1 " Ethnologische Bemerkungen iiber die Papuas der Maclay-Kiiste in 

 Neu Guinea— Alltagiges Leben der Papuas" (Fortsetzung). Reprmtedfrom 

 the Natuurkundig Tijdschrift '-cor Nederlan.Uch Indie; Zevende Serie, 

 Deel vi. p. 294. (Batavia, 1876.) This abstract may be regarded as a con- 

 tinuation of two articles by me upon the same subject, which were published 

 in Natukb, vol ix. p. 328, vol. xiv. pp. T07, 136.— J. C. G. 



