206 Scientific Intelligence — Chemistry and Mineralogy. 



ments, and stated that he was engaged in a chemical examination of this 

 curious substance, and expected to have an early opportunity of men- 

 tioning the results he had obtained. In the meantime, he said that he 

 found it to contain, amongst other constituents, a few per-cents of an 

 azotised substance, which, so far as he had hitherto examined it, had all 

 the properties of vegetable casein. It also contained a very little albu- 

 men. These seemed to be the principal azotised constituents. 



10. Galvanic Silvering of Cast-Iron. — Professor Connell lately exhibited 

 to the Society of St Andrews the process of galvanic silvering of cast- 

 iron. The liquid employed for this purpose was that suggested by M. 

 Tewreinoff of St Petersburgh, and consists of a strong solution of moist 

 chloride of silver and cyanide of potassium in water. The galvanic 

 power employed by Mr Connell was two pairs of Smee's plates, the 



Wildenow changed the name, without sufficient reason, to Elephantusia macro- 

 carpa ; but his bad example is not followed. The natives of Columbia call it 

 Tagua, or Cabeza de Negro (Negro's head), in allusion, we presume, to the figure 

 of the nut. Almost all we know about it is contained in the following memo- 

 randum, published by the Spanish writers above mentioned : — " The Indians 

 cover their cottages with the leaves of this most beautiful palm. The fruit at 

 first contains a clear insipid fluid, by which travellers allay their thirst ; after- 

 wards this same liquor becomes milky and sweet, and it changes it taste by de- 

 grees as it acquires solidity, till at last it is almost as hard as ivory. The liquor 

 contained in the young fruits becomes acid if they are cut from the tree and kept 

 some time. From the kernels the Indians fashion the knobs of walking-sticks, 

 the reels of spindles, and little toys, which are whiter than ivory, and as hard, 

 if they are not put under water ; and if they are, they become white and hard 

 again when dried. Bears devour the young fruit with avidity." The tree which 

 furnishes these nuts is a palm, although Humboldt and Kunth have referred it, 

 for some reason with which we are unacquainted, to the order of Screw Pines 

 (Pandanaceae), an error which is preserved by all botanists up to the present day. 

 Two species are known, the Phytelephas macrocarpa, or large-fruited, and micro- 

 carpa, or small-fruited. The part of the kernel which is^ thus similar to ivory 

 is what is called the albumen ; that is to say, the nutritious substance which sur- 

 rounds the embryo, and which is destined to feed it when it begins to grow. 

 It is of the same nature, though not of the same consistence, as the flour of corn, 

 the spicy substance of the nutmeg, and the meat of the cocoa-nut, which in other 

 palm-trees becomes very hard : that of the Date Palm is quite as hard, if not 

 harder ; but it is not white enough or large enough to be worth using by the 

 turner. The Doum Palln, or Forking Palm, of Thebes, the fruits of which are 

 called gingerbread-nuts at Alexandria, has a similar albumen, which is turned 

 into beads for rosaries ; and our correspondent Mr Murray informs us that he has 

 a model of the Double Cocoa-nut, or Coco de Mer, beautifully carved from a 

 portion of its own albumen, as hard as ivory, and susceptible of as fine a polish. 

 He says he has also seen a figure, cut from the same specimen, forming the end 

 of the shaft of a lady's parasol, not to be discriminated from one carved in ivory. — 

 Crardeners' Chronicle. 



