398 



NATURE 



[August 8, 1878 



and, fusing from the bottom side, gradually dissolved. I then 

 placed similar blocks of metal endwise on, vhen, dipping be- 

 neath the surface, they bounded back to the surface, and subse- 

 quently dissolved, endway down. These results apply to various 

 weights and sorts of compounds. I then conducted similar ex- 

 periments with cast-iron, and found that the facts were still 

 more conspicuous in the cast-iron (all of the fame tendency) 

 than in brass. 



" Placing the iron on the surface of the liquid iron, a rapid 

 chill set in, and a coating of iron, apparently about V' thick, 

 attached itself to the cold iron, but very shortly re-melted, when 

 the cold iron disappeared with it. I then dropped a small piece 

 of cold iron (the same being dried to prevent explos-ion) endwise 

 on to the surfaces of the liquid metal, when, bounding back to 

 the surface, it melted in that position. 



" The argument applies precisely to the experiments conducted 

 in lead. 



* ' In all cases the cold metals w ere relieved of any exterior 

 ingredient by being well filed over. In every case of brass and 

 iron the material melted was about l" in diameter and 4" in 

 length, each piece being round. With regard to the lead, the 

 pieces varied in size, weight, and form, but all the experiments 

 resulted in the rame way. " Joseph Whitley " 



"Rail-way Works, Leeds, April 11, 1878 



" My dear Dr. Muirhead, — Confirming my letter of yes- 

 terday, I have now to report the results of several experiments 

 which, you will see, perfectly coincide with and demonstrate the 

 truth I have again and again assured you of, viz., that all 

 liquid matters that are susceptible of solidification will, when 

 solid, float upon similar matter when in a liquid state. 



" I intimated to you in my last that I feared I could not, 

 in a small crucible, sufficiently fuse granite and whinstone, and 

 in my experiments of yesterday, although I melted my crucible, 

 I did not sufficiently liquefy the granite so as to float a piece 

 upon the liquid mass. I therefore deferred further manipula- 

 tions till to-day, and having secured a quantity of whinstone, I 

 also determined to alter my course and to take advantage of 

 a much larger focus of heat than that of a furnace 30" X 20" X 

 20", with a 6olb. crucible. So I called upon Messrs. Taylor 

 Bros, and Co., ironmasters of this town, and with their permis- 

 sion I proceeded as follows : — 



" Being passed over by their manager to a subordinate 

 officer — a worthy and very intelligent fellow, and, by the way, 

 a strong believer in the doctrine that matter sinks in like 

 matter when melted — we went to a furnace where we had 

 three tests with whinstone, which he said disappeared, and 

 I believe that he was justified in the two first experiments, 

 because he was not sufficiently up in his observation as to 

 notice a stream of gas liberated from a bubble formed on the sur- 

 face by the melting of the whinstone immediately under it. In the 

 next furnace we went to we had a large quantity of liquid 

 * cinder ' ' tapped out ' of a furnace into a trough. I really w ish 

 you could have seen it ; to me the sight was grand, the gases 

 given off" by the melting of the whinstone blazed with a sort of 

 blending of tints of purple, yellow, and green. I never saw 

 anything so fine in flame. The whinstone was like a thing of 

 life, so buoyant — of course the specific gravities of the liquid 

 and solid materials varied considerably, and hence the buoyancy 

 of the whinstone. We then tried a large number of small 

 pieces of cinder — same as the liquid mass before us ; but my 

 friend the officer insisted that they went to the bottom — they 

 certainly, except in one instance, never returned to the surface, 

 because they liquefied before they had time to rise. My 

 whinstone being done, and seeing that the results were not so 

 satisfactory to my friend, I remarked that I was prepared to go 

 all day and all night rather than give up the task of convincing 

 him that his conclusions were wrong. I therefore suggested we 

 should take a larger furnace, and deal with larger masses. We 

 therefore, instead of dealing with quantities of 8 oz. weight, 

 and weights of i lb., took pieces of 5 and 6 lbs, weight, 

 each of solid cinder. Had my faith not been implicit I might 

 have been deceived, for No. i, 2, and 3 pieces went to the 

 bottom, and my friend said, ' Now are you satisfied ? ' and I 

 replied ' No, I am not.' Imagine his astonishment when 

 No. I came bounding to the surface, and floated about like a 

 cork, when the mass of heat had dissolved the coating which it 

 clothed itself in at entering the bath and had begun to melt the 

 original piece, up came No. 2 and 3, and I let him float them about 

 on the surface with an iron rabble, so as to sear, as it were, the 



lesson sufficiently deep into his soul that it might never be 

 erased. There were eight or nine jolly fellows looking on, and 

 who enjoyed the joke, when my friend took off" his hat and 

 bowing politely said, ' Well, I am exceedingly obliged for the 

 lesson you have taught me, and I shall never forget that all 

 solid matter floats upon like matter when melted, as ice floats 

 upon water.' Of course I had a joke and told him he was only 

 one of a few who believed in the doctrine, and that he was the 

 last convert. "Joseph Whitley" 



P.S. — In the name of science I take this opportunity of ten- 

 dering to Messrs. Taylor Bros., of the Clarence Iron Works,. 

 Leeds, my grateful thanks for their generous acquiescence in 

 my request, and the facilities they kindly rendered in the expe- 

 riments. — J. W. 



THE INFLUENCE OF LIGHT UPON 

 BIOPLASM^ 



C OME twelve months ago we briefly recorded in Nature the 

 •^ results of our observations on the effect of sunlight on 

 bacteria, and other organisms commonly associated with putre- 

 faction and decay. Most of the experiments were subsequently 

 described in detail in a paper communicated to the Royal 

 Society, The chief of our earlier conclusions may be summed 

 up shortly as follows : — 



1. Light is inimical to, and under favourable conditions may 

 wholly prevent, the development of these organisms, its action 

 on the common forms of bacteria being apparently more power- 

 ful and rapid than upon the mycelial fungi which are prone to 

 appear in cultivation-fluids. 



2. This action appears to attain its maximum in the waves of 

 greatest refrangibility. It is demonstrable in yellow light, but 

 towards the red end of the spectrum sinks to a minimum, 



3. The fitness of the cultivation-fluid to act as a nidus is not 

 impaired by the insolation. 



We found, moreover, that tubes containing a cultivation fluid 

 and plugged with cotton wool, when removed to a dark place 

 after exposure to the sun fon a sufficient period remained perfectly 

 clear and free from organisms for months. We thought 

 therefore, that the " germs " in these solutions had been com- 

 pletely destroyed by the solar rays. 



While, however, we believe that, if the insolation be suffi- 

 ciently prolonged, all the germs or spores originally present 

 may be killed, and that, as regards bacteria, the insolation, 

 under favourable conditions, need not be of very long diu-ation 

 we have reason to think that, by cell-walled organisms, the 

 destructive action of light may be resisted for a considerable 

 period, and that the first result is to reduce the spore to a state 

 of torpidity in which it may lie dormant for many months. 



The investigation of this point, however, must necessarily 

 extend over a long time ; and in the above remarks we would 

 wish to be understood as off"ering a suggestion rather than a 

 definite conclusion. 



We noticed last year that sunlight had no retarding eff"ect on 

 the action of the "indirect ferments," or, at least, of the soluble 

 ferment of yeast {zymase of Bechamp, ferment inversive of 

 Berthelot), which we used for our experiment. More recently, 

 however, we have tested the eflfect of prolonged insolation on 

 the soluble ferment itself, and have found that, at the end of 

 three weeks' exposure to a midsummer sun, the zymase had 

 entirely lost its characteristic property of hydrating cane-su^ar, 

 while a corresponding specimen, which had been kept in ''the 

 dark, still retained its energy. It would appear, therefore, that 

 the action of light affords no means of distinction between the 

 "organised " and the " indirect " ferments. 



"We have attempted to elucidate the intimate nature of this 

 action of light upon the organisms which have formed the sub- 

 ject of our experiments, and we have evidence pointing strongly, 

 as we think, to the solution of the problem. Early in 1877 we 

 set ourselves to this task, and, in order to obtain some insight 

 into the effect of light upon certain organic bodies, we made a 

 number of observations upon oxalic acid. 



We have elsewhere 2 shown that a solution containing 0-63 

 per cent, (decinormal) is entirely decomposed by a somewhat 

 prolonged exposure to strong sunlight when air is present. We 

 now find that in a corresponding solution, in vacuo, no change 



1 By Arthur Downes, M.D., and T, P. Blunt, M.A. Oxon, 



2 Chemical News. 



