426 



NATURE 



[Makcii 2, 1899 



commodity compares wiih that of thiity years ago, reference 

 may be made to some statistics quoted by Dr. I'. L. Simmonds 

 in 1878. From these it appears that in the year 1S70 the total 

 imports of tortoiseshell (apparently of all descriptions) into the 

 United Kingdom were 49,332 lbs., valued at 32,503/. It is also 

 stated by th^same writer, that in some years prior to 1878 the 

 amount of the imports had reached the enormous total of thirty 

 Ions, with an estimated value of 74,000/. In 1870 the average 

 price per pound was between thirteen shillings and fourteen 

 shillings and sixpence ; except Indian shell, which was only 

 worth Ts. gd. the pound. Dr. Simmonds likewise mentions that 

 whereas about the year 1845 selected .samples had realised as 

 much as 3/. 3/. per pound ; between that time and 1S70 there 

 had been a great fall in values, although towards the latter date 

 they showed a tendency to rise. For instance, somewhat before 

 that year good coloured shell from Zanzibar and Singapore had 

 fetched from 281. to 2<)s. bd. per pound, and fair to good 

 qualities of West Indian from 3l.f. to 41.1. the pound. 



According to the reports issued by Messrs. Lewis and Peat 

 for 1898, the total amount of hawksbill tortoiseshell (that is 

 to say exclusive of loggerhead shell, which is referred to later 

 on) offered for sale in London during that year was about 

 76,760 lbs., practically all of which was sold. To arrive at the 

 average price realised at these sales, would involve long calcu- 

 lations without affording any very compensative advantage. 

 .\ttention may accordingly be directed to certain special values. 

 The highest prices realised during the year were at the May sale, 

 when selected Zanzibar and Bombay shell .sold at from 67.?. (jd. 

 to wzs. (xi. per pound, while two pounds weight of specially 

 selected Sydney and Fiji were disposed of at the rate of lOOs. 

 per pound. Whether these are record prices, we have no in- 

 formation ; but they are certainly ahead of any of those quoted 

 by Dr. Simmonds in 187S, 8oj. per pound being the maximum 

 value mentioned by him. The next highest price during 1898 

 was 95.f. per pound for selected heavy Zanzibar and Bombay 

 shell of a reddish tint, which was disposed of in the September 

 sale. This value is followed by prices ranging between 45^., 

 62/. 61/., and 75^. for selected Nassau and Honduras shell in 

 the West Indian class ; Jamaica and Havana shell touching, 

 however, as much as 77r. the pound. Of West Indian " hoof," 

 the best Nassau and Honduras pale-coloured descriptions 

 realised from iS.t. to 27^. at their lop price; while ordinary 

 West Indian was a few shillings cheaper. On the other hand, 

 Zanzibar and Bombay "hoof" ranged between 6.r. and 17^. 6rf. 

 .Some of the highest prices were realised by Nassau and 

 llondur.is "yellow-belly," which fetched between 67j'. bd. and 

 SOi. in September, but had fallen to between 45.1. and 65^. per 

 pound by November. " Vellow-belly " is, or was, extensively 

 used by Spanish ladies for large hair-combs, being often much 

 more esteemed for this purpose than the mottled upper shell. 

 Among all the classes of hawksbill tortoiseshell, that from 

 Ceylon seems to have the lowest value ; the general quotation 

 being between 14^'. and 17^., although as much as 34s. has 

 been obtained for selected samples. 



The tortoiseshell yielded by the loggerhead turtle, of which 

 8200 lbs. were offered and about 7300 lbs. sold by Messrs. 

 Lewis and Peat during 1898, is a much less valuable commodity 

 than the produce of the hawksbill. During the year in ques- 

 tion, the usual price per pound ranged between one and three 

 shillings, although as much as 4.1. go*, was obtained in March. 

 The upper plates of the loggerhead are much thinner than those 

 of the hawksbill, and of a more or less uniform dark chestnut- 

 brown, without marked translucency. 



The statistics quoted above afford a good general idea of the 

 vast extent and value of the London tortoiseshell trade. Un- 

 fortunately, it is impossible to give the total British imports and 

 iheir value, since in the Board of Trade returns tortoiseshell, 

 together with mother-of-pearl, is lumped with other shells, and 

 the value of the mixed imports alone given. In addition to the 

 British trade, the imports of other European countries (although, 

 of course, some of these may have come from Britain) are 

 very large. France, for instance, is a very large importer of 

 tortoiseshell, the average annual amount taken during the ten 

 years ending with 1876 being 42,306 kilogrammes, with a value 

 of 2,078,910 francs. China and Japan are likewise large con- 

 sumers of tortoiseshell, as is also America. The annual de- 

 struction of hawksbill turtles to supply the demand for this shell 

 nuist therefore be enormous ; but since, like most marine 

 creatures, these reptiles are exceedingly prolific, it by no means 

 I'lllows that they are in any imminent danger of extermination. 



NO. I 53 I, VOL. 59] 



As regards its employment in the arts and manufactures, 

 tortoiseshell being very similar in its nature to horn, is in like 

 manner made partially plastic before working by immersion in 

 hot water in which salt has been dissolved. The natural 

 curvature of the plates is removed by placing them under 

 pressure between smooth boards while in this semiplastic con- 

 dition, and allowing them to cool. But, in addition to its 

 plasticity, tortoiseshell pos.sesses the valuable property of weld- 

 ing ; so that when a large superficies is required, two or more 

 plates can be readily joined together in this manner. The 

 modus operandi is first of all to bevel the adjacent edges of the 

 two plates to be united in opposite directions, and then pressing 

 the overlapping edges together in a metal press under the action 

 of boiling water. So intimate is the union, that when the 

 operation is properly performed, no trace of the division is 

 visible. Nor is this all, for by the application of moist heat 

 tortoiseshell may be made to receive impressions of any form 

 by being squeezed between metallic moulds. Neither are the 

 dust and shavings made in the course of the manufacturing 

 processes useless, for these are placed in brass moulds, where, 

 under moist heat and pressure, they become consolidated into 

 a homogeneous mass of any form that may be desired. Neck- 

 laces and many other small fancy articles are made in this 

 manner. 



From its high price, it is important to economise as much as 

 possible the material used in the manufacture of tortoiseshell 

 objects. The following ingenious example of this is described 

 by Dr. Simmonds. "In making the frames for eye-glasses, 

 narrow strips of tortoiseshell are used, in which slits are cut 

 with a saw ; the slits being subsequently, while the shell is 

 warm, strained or pulled open, until they form circular or oval 

 apertures, by the insertion of tapering triblets of the required 

 shape. The .same yielding or flexible prop.^rty is made use of 

 in the manufacture of boxes, a round flat disc of shell being 

 gradually forced, by means of moulds, into the form of a circular 

 box with upright sides." The only objection to this process is 

 that the colours become so darkened as to be almost black. 



In the manufacture of small combs, again, a pair of these are 

 cut out of a single piece of shell by means of a vertical cutter, 

 working in such a manner, that the cores left between the 

 teeth of one comb form the teeth of the other. Similarly in 

 buhl-work cabinets, in which tortoiseshell is inlaid with brass, 

 both portions of the former material cut out by the fret-saw are 

 employed. Hence in a pair of cabinets the pattern of the 

 inlaying is reversed ; the tortoiseshell forming the ground-work 

 and the brass the inlaying in one, while in the other the oppo- 

 site arrangement occurs. 



Formerly the manufacture of ladies' combs, especially those 

 made for Spain and South America, formed a very important 

 feature in the tortoiseshell industry, some of these being a 

 couple of feet in width, and from six inches to a foot in height. 

 In England, at any rate, large combs are now disused. 

 Although for veneering purposes, when the colouring of the 

 shell is intensified by a layer of coloured varnish or metallic 

 foil beneath it, thin tortoiseshell is employed ; the thick de- 

 scriptions are these most favoured at the present day in the 

 English market. 



F'inally, it may be mentioned that on the continent the shell 

 of various species of land tortoises is employed more or less 

 extensively for bubbwork, its colour being alwajs intensified by 

 a substratum of bright foil ; and it is said that the same 

 material has occa.sionally been employed for inlaying purposes 

 in England. Imitation tortoiseshell is made by painting horn 

 with a paste of lime, litharge, and soda, which is allowed to 

 dry and then rubbed off. Dark spots of lead sulphide are thus 

 formed in the horn, giving it a mottled appearance. 



R. L. 



UNIVERSITY AXD EDUCATIONAL 

 INTELLIGENCE. 



OxiORh.— Prof. W. F. R. Weldon, F.K S., has been ap- 

 jxiinted to the vacant Linacre Professorship of Coi«i)arative 

 Anatomy, in succession to Prof. Ray Lankester, F.R.S. 



Reading College, Reading, has been admitted to the privileges 

 of an affdialed college. 



Natural Science scholarships are announced for competition 

 at the following colleges :— lesus College, on .April 18 ; Merlon 

 College, New College, and "Corpus Chiisli College, on June 27. 



