Dec. 2, 1886] 



NA TURE 



human body, with Ught in the sky, with purity and hard- 

 ness in the earth ; death, night, and pollution of all kinds 

 being colourless." 



I must briefly turn to the concluding part of our subject. 

 It has long been known tl".at thin films of certain metals 

 and certain metallic oxides act on light in the same way 

 as thin films of other translucent substances. I have here 

 such thin films of o.xide of lead, which, many years ago, 

 Nobili, Becquerel, and Gassiot taught us to deposit, and 

 such films have since been used in decorative metal-work. 



[Beautiful examples of such films were projected on the 

 screen.] 



I wish I had time to point to the great interest and im- 

 portance of films of coloured oxide of iron in the temper- 

 ing of steel, for it is well known that, apart from the 

 scientific interest of the subject, the shades from straw- 

 colour to blue which pass over the surface of hardened 

 steel when it is heated in air, aflbrd precious indications 

 as to the degree of temper the metal has attained, and 

 in no industry is this better shown than in the manu- 

 facture of steel pens. I must pass this over, and turn to 

 one other instance of the formation of coloured films on 

 metals. Here is an ordinary plumber's ladle filled with 

 lead, which will soon be molten when it is placed over 

 this flame. The air will play freely on the surface of the 

 melted lead, and, as a certain temperature is reached, 

 very beautiful films will pass over the surface of the 

 metal. If the lead contains very minute quantities of 

 cadmium or of antimony, the effect will be greatly height- 

 ened. If the light from the electric lamp be allowed to 

 fall on the surface of the bath of lead, it will be easy to 

 throw the image of the metallic surface on the screen, 

 and you will see how beautiful the films are and how 

 rapidly they succeed each other when the metal is 

 skimmed. What, then, is the special significance of the 

 experiment from our point of view ? It represents in a 

 singularly refined way the one experiment which stands 

 out prominently in the whole history of chemistry ; for the 

 formation of a coloured scum on lead when heated in air 

 has been appealed to, more thany any other fact, in sup- 

 port of particular sets of views from the time of Geber in 

 the seventh century to that of Lavoisier in the eight- 

 eenth. It was the increase in weight of the lead when 

 heated in air that so profoundly astonished the early 

 chemists ; and, finally, the formation of a coloured oxide 

 by heating lead in air was the important step which led 

 on your great townsman, Priestley,' to the discovery of 

 o.xygen ; and, as the fact of his residence among you will 

 never be forgotten, Birmingham may claim to have been 

 connected, through him, with one of the most splendid 

 contribution ever offered to Chemical Science. 



NOTES 

 Prof. Rucker, F.R.S., has been appointed by the Lord 

 President of the Council to the Professorship of Physics in the 

 Normal School of Science and Royal School of Mines, rendered 

 vacant by the death of Prof. Guthrie, F.R. S. 



At the Royal Society on Thursday last (November 25) a paper 

 was read by Sir Richard Owen, containing some further evidence 

 on the structure of the very remarkable extinct mai-supial, 

 Thylacoleo carnifex. The author re-affirmed his previous state- 

 ments that it was a carnivorous beast of the size of a lion, the 

 probable prey of which had been the larger herbivorous marsu- 

 pials, also now extinct. Prof. Flower, after reviewing the 

 additional evidence that bad been adduced, repeated his convic- 

 tion expressed eighteen years ago in a paper read before the 

 Geological Society, that the dentition of Thylacolcj found no 

 parallel in any existing predaceous carnivore, but was formed on 



* He pointed out that the experiment with minium confirmed his view that 

 he mercury calcined in air derived oxyg<tn/rom the air. 



a totally different type, and that there was therefore no justifica- 

 tion for assigning to it habits for which it did not seem particu- 

 larly well adapted. The essential conditions in a dentition 

 which would enable an animal to seize and overcome large and 

 struggling prey, as seen in both lions, tigers, wolves, and the 

 existing carnivorous marsupials, are large canines set well apart, 

 with incisors so small as not to interfere with their piercing 

 action ; whereas in Thylacoleo the canines are rudimentary, and 

 the central incisors greatly developed. The alternative, some- 

 times suggested, that the animal was herbivorous, was equally 

 improbable. In fact, it would not be safe to do more than 

 speculate on the habits or food of an animal the dentition of 

 which was so highly specialised, and without any analogy in the 

 existing state of things. Prof. Huxley said that he agreed with 

 the conclusions of the last speaker. 



A COURSE of six lectures, adapted to a juvenile auditory, on 

 " The Chemistry of Light and Photography " (with experi- 

 mental illustrations), will be given at the Koyal Institution by 

 Prof. Dewar, M.A., F.R.S., on the following days, at three 

 o'clock : — Tuesday, December 28, 1886 ; Thursday, December 

 30; Saturday, January I, 1887 ; Tuesday, January 4 ; Thursday, 

 January 6 ; Saturday, January 8. 



The Royal Society have just received from Egypt a consign- 

 ment of specimens of the different strata of soil in the Delta. 

 The borings have been carried out to a depth of nearly 200 

 feet, and the solid bottom has not yet been reached. The 

 Royal Engineers in Egypt have been intrusted with the work. 

 The specimens, which are chiefly of sand and clay strata, are 

 deemed of great importance, and the .Society has granted 

 money for the continuance of the work, which will be carried 

 out by the detachment of Engineers as hitherto. 



The Secretary of State for War has given permission for Sir 

 Frederick Abel, C.B., the Chemist of the War Department, to 

 accept the post of organising secretary to the Imperial Institute, 

 provided that the duties do not interfere with those of his 

 appointment under the War Office ; and Sir Frederick Abel has 

 been desired by the Prince of Wales, President of the Imperial 

 Institute, to enter upon his work as soon as possible. The new 

 secretary has just completed his work in connection with the 

 electric lighting of the Indian and Colonial Exhibition, and is 

 also retiring from his duties in connection with the Society of 

 Arts. 



On' November 17, at 7h. i8m. p.m., a fine fireball was seen 

 at Stonyhurst College, Blackburn. It appeared to be several 

 times as bright as Venus. In colour it was violet, and of a 

 distinct pear shape. The part of its path observed, as far as 

 could be judged from the stars seen through detached clouds, 

 was from near 1 Ceti to the small stars above Fomalhaut, about 

 88 Aquarii. Its path was slightly curved. So brightly did it 

 shine that attention was first called to it by the illumination of 

 the sky, although seen from a room in which the gas was lighted. 



The Morning Star of Jaffna, in Ceylon, reports the death of 

 the taxidermist of the Victoria Museum in that town from the 

 bite of a cobra, under very curious circumstances. While 

 feeding a cobra, which he had supposed was harmless from 

 previous extraction of the poisoa-bag, it suddenly bit his hand. 

 For a few minutes he took no notice, thinking the bite harm- 

 less, but pain and nausea soon began. Carbolic acid was 

 applied, ligatures were bound round the arm, an incision was 

 made at the bite, and the blood of the arm was wholly re- 

 moved. Various antidotes were used, but the unfortunate man 

 lost the power of speech, and soon afier every muscle seemed 

 to have become paralysed, and breathing entirely ceased. 



