462 TRANSACTIONS OF THE 



tenth of the gold. Where diamonds are plenty, gold and platinum are 

 scarce. Some of the ore of platinum contains grains of cinnabar. 



The platinum ore of Banjarmassin, separate^ hy hydrochloric acid gives, 



Iron oxide and iron , 1.13 



Copper, 0.50 



Gold 3.97 



Platinum, , 70.21 



Osmium, 1.15 



Iridium, 6.13 



Palladium, 1 . 44 



Rhodium., 0.50 



Iron, 5 . 80 



Copper, . 34 



Insoluble in aqua regia, osmiridium and minerals, 8. 83 



The platinum appears in small circular or oval laminae, like drops lamin- 

 ated, as if struck with a hammer — seldom has any facettes. The gold in it 

 is like pepitas in miniature, microscopic nuggets. South American plati- 

 num resembles it. Last year, Mons. Chapins, of Paris, stated that rhodium 

 alloyed with platinum could be hammered and laminated readily. Aqua 

 regia cannot attack it, rendering it therefore very valuable to the practical 

 chemist. 



Batchelder's American patent, takes iridium, alloyed with copper for 

 etching. Rhodium is worth, according to its degrees of purity, from $7, 

 to $'250 an ounce. The residue of platinum ore is now worth SlOO a pound, 

 and a few years ago it sold for S20 a pound. 



April 2dth, 1858. 

 The first conversazione of the present session was held on Saturday 

 evening last, at the Society's house. The whole of the rooms were thrown 

 open, and in the great room was displayed a series of upwards of sixty 

 drawings of curious modes of marine propulsion, prepared and kindly lent 

 by Mr. J. MacGregor. Models, also, patented from 1794 to 1850. Mr. 

 Tompkins kindly attended with his Ross' finest microscope and infusorial 

 animals. Also an historical series of telegraphs, including Wheatstone's 

 first six-line wire needle telegraph, and the needle instruments at present 

 in general use. Wheatstone's magnetic electric dial and capstan instru- 

 ments ; Baines' chemical telegraph ; Highton's single needle ; Henley's 

 needle telegraph ; Siemen's and Halskel's indication relay and magnetic 

 dial, and their recording instrument for sub-marine lines ; Varley's. These 

 instruments were in operation during the evening. Specimens of all the 

 cables were exhibited ; locomotives, engines, new life boat, &c., &c. 

 The Society holds two conversazione in April and May. 



IRON BUILDING. 



Her Majesty's commissioners in 1848 tried experiments on the strength 

 of iron, relative to violent concussions, vibrations, &c. Loaded cars, run 

 down inclined planes, and along iron bars placed horizontally at the bot- 



