February i, 1894] 



NA TURE 



319 



had their appointed places in which they were always to 

 be found. This habit of order made him an admirable 

 collector, and I well remember, on visiting Kew after my 

 return from the Amazon, the late Sir William Hooker 

 took out some bundles of plants collected by Dr. Spruce 

 and pointed out to me how well chosen and beautifully 

 preserved they were, notwithstanding that they had been 

 collected in one of the very moistest climates in the 

 world, in which the care and labour required to produce 

 such a result was very great. He was quick at languages ; 

 spoke and wrote French with ease ; and in South 

 America rapidly acquired the Portuguese and Spanish 

 languages, for the latter of which he had a great admira- 

 tion. He had literary tastes, and was fond of the old 

 poets ; he was full of anecdote, and even when suffering 

 from illness an hour would rarely pass without some 

 humorous remark or pleasant recollection of old times. 

 He was an advanced Liberal in politics, a true lover of 

 the working classes, and nothing more excited his indig- 

 nant wrath than to hear of the petty, but cruel, per- 

 secutions to which they are often subjected. In all his 

 words and ways he was a perfect gentleman, and to 

 possess his personal friendship was a privilege and a 

 pleasure. 



Of his merits as a botanist it must be left to experts to 

 speak ; but his writings show that he had great powers 

 of observation, and that nothing escaped him that could 

 throw light on the peculiarities of the grand and luxuriant 

 vegetation among which the best years of his life were 

 passed. His papers and letters sufficiently prove that he 

 possessed a clear and picturesque style of writing, and it is 

 to be hoped that the journals kept during his fifteen years' 

 exploration, which he was himself unable to prepare for 

 publication but which must be full of interesting matter, 

 may soon be given to the world. His sole executor is 

 his old friend and neighbour, Mr. Matthew B. Slater, of 

 Malton. A. R. W. 



PRECIOUS STONES. 



/^NLY twenty-five years have elapsed since the exist- 

 ^^ ence of diamonds in South Africa was first made 

 known, and during that period the diamond trade of the 

 world has undergone a complete revolution. The work- 

 ing of diamond gravels in Brazil has been almost entirely 

 abandoned, while the search for the gem in India, 

 Borneo, and other districts has been seriously dis- 

 couraged. The export of rough diamonds from South 

 Africa rose gradually from 200 carats in 1867-68 to 

 3,841,937 carats in 1888, when it attained a maximum: 

 since that date, however, there has been a slight decline 

 in the output of the mines. The annual value of the 

 diamonds raised in South Africa now exceeds ^^4,000,000. 

 Strange to say, the discovery of the new and abundant 

 source of diamonds has not had any serious effect in 

 diminishing the market value of the gem. When the 

 diamond was first discovered in South Africa, the esti- 

 mated value per carat of the rough stones was about 

 ^i lay.; in 1890 the price had risen to £\ i^s. 2,d., and 

 last year it declined to /i 5^-. 8^. 



The foregoing particulars are taken from a recently 

 published book which gives an admirable account of 

 the origin of the diamond industry in South Africa, 

 and of the successive changes made in the method 

 of mining and washing the " blue-earth " which yields 

 the gems.i This work originally appeared as a guide 

 to the Kimberley exhibition of 1892, and contains so 

 much valuable information in a small compass, that the 

 author has been well-advised in issuing it in its present 

 more permanent form. 



1 "Diamonds and Gold in South Africa." By Theodore Reunert, 

 M.Inst.M.E., Assoc. M.Inst.C.E., with Maps and Illustrations. (London : 

 E. Stanford; and Capetown, Port Elizabeth, and lohannesburg : I. C. 

 Juta and Co., 1893.) 



NO. 1266, VOL. 49] 



The working of the celebrated mines about Kimber- 

 ley was commenced by adventurers working indepen- 

 dently in their claims. But as the mining was carried 

 to greater and greater depths, combined action became 

 necessary, and gradually the claims were amalgamated 

 and bought up by large companies. 



Up to the year 1872 the working of the claims in the 

 South African mines was carried on by a system of road- 

 ways, which were laid out when the concessions were 

 first granted. About the date named, the use of these 

 roads had to be abandoned in favour of a system of haulage 

 by wire ropes — these making a network over the whole 

 of the mines. The appearance of the mines under these 

 two systems of working is admirably illustrated by photo- 

 graphs in the work before us. By the year 18S4, the 

 mine at Kimberley having been carried to a depth of 40a 



Exact size and shape of a diamond found in the De Beers Mine, and exhi- 

 bited at the Paris Exposition, 1889. Weight, before cutting, 428^ 

 carats, after cutting, 228^ carats. 



Diamond found in Jagersfontein Mine in June 1S93. Length (a) ai in.; 

 greatest width (b) 2 in. ; smallest width (c) ij in. Thickness at {b) end 

 ij in.; thickness at (c) end 5 in. Extreme girth in width (taken from 

 e to d) 5g in. Extreme girth in length (taken from y to g) 6| in. Gross 

 weight 969J carats. 



feet, and heavy falls of material having produced serious 

 loss and inconvenience, it was felt that the time had 

 come for carrying out a totally different system of mining 

 there. Accordingly, in that year, inclined shafts, 

 starting from the surface, outside the limits of the mine, 

 were put down, and these inclined shafts have been since 

 superseded by vertical ones. 



The changes in the working of the Kimberley Mine 

 have been followed by similar alterations in the nature 

 of the operations carried on in the three other great mines 

 in its immediate neighbourhood — De Beers, Bultfontein, 

 and Dutoitspan. These four mines are in the vicinity of 

 the townships of Kimberley and Beaconsfield in the 

 British colony of Griqualand West. The only other im- 



