1880.] On the Artificial Formation of the Diamond. 459 



further experiments. A list of disasters now awaited me. Eight 

 tubes failed through bursting and leaking, and one of the explosions, 

 when two were being heated together, destroyed a part of the furnace 

 and injured one of my workmen. Besides this, two tubes were spoiled 

 in welding. However, I had four experiments after this, all with- 

 standing the pressure, and in one of these, with 10 per cent, bone oil 

 and 90 per cent, paraffin spirit, a small quantity of diamond was found. 

 The contents of this tube were different from the other successful one, 

 being much looser and not in the same hard mass as the first. In 

 another series of six experiments two were at first thought to have 

 been successful, but I afterwards found that one of them was not so, 

 the transparent matter being siliceous, but insoluble in cold hydro- 

 fluoric acid, although it dissolved on boiling. The uncertainty and 

 great expense involved in using these forged coils of iron with tubes 

 bored out of the solid induced me to again try steel, and Messrs. 

 Cammell and Co. having prepared some tubes for me, I tried them, 

 but with the same results — they exploded into fragments at a red- 

 heat. And herein they are much more dangerous than coiled tubes, 

 because the latter seldom fly into fragments, but just tear open a little. 

 A further unforeseen danger in using steel tubes was discovered. One 

 which had stood the heating very well was being bored, and when the 

 inner skin was cut so that the gas rushed out, the whole exploded, 

 endangering the life of the workman who was boring, but as he was 

 standing at the end of the tube and the pieces flew laterally he was 

 not hurt. I have performed over eighty experiments, and have only 

 obtained three results of a successful nature. The identification of the 

 crystalline pieces as carbon was easy enough, but I have been anxious 

 to find whether they are pure carbon or a compound with some other 

 element, and to that end the following experiments were conducted. 



A portion of the substance from the first successful experiment was 

 weighed out after it had been freed from all foreign matter adhering 

 to it, and placed in a very small platinum boat made of a strip of thin 

 foil, the ends of which were wrapped round two stout platinum wires 

 which were sealed into a wide glass tube. The carbon particles were 

 transferred to this boat after being weighed, and the tube connected 

 by india-rubber stoppers with an oxygen gasometer on the one side 

 and a series of potash bulbs on the other. The oxygen was dried over 

 solid caustic potash before entering the tube, and again after leaving 

 the potash bulbs. The carbon (14 mgrms.) having been weighed out, 

 the potash bulbs were weighed, and a current of oxygen passed 

 through the apparatus, and the platinum wires connected with a 

 battery strong enough to heat the foil to a bright red-heat. After a 

 few minutes the oxygen was stopped and the bulbs weighed, when it 

 was found that they had gained 1 mgrm. On repeating this operation 

 no gain was found, the moisture having been entirely driven off by the 



