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NA TURE 



\J'une 23, 1887 



Williams at a certain price. This seemed to me so low that I 

 asked them about it, when they did inform me that the reason was 

 its occurring as a by-product. Nothing whatever was then said, 

 however, about being " impure " ; on the contrary, they inclosed 

 two small fragments, one of which they said they sold as "pure," 

 and the other (at half price) as "impure." The last was a light 

 yellow-brown colour, and I never meddled with it ; of the other 

 I purchased an ounce for trial. On finding so much silica and 

 soda I wrote them reporting, and asking if the sample was 

 reduced by the hyposulphite process, as Dr. Draper had men- 

 tioned the difficulty of getting a pure product in that way. They 

 replied that hyposulphite was used, and that the "pure "sample 

 might possibly contain soda, but they thought not silica ; the other 

 sample might contain sodn, silica, and probably iron. I wrote 

 again pointing out that oxyhydrogen illumination was the most 

 likely use for the product, and asking if they could not purify it 

 further at an enhanced price, when they declined, as they state. 



The difference is, that all this took place o/?^;- I had purchased 

 and tested the sample, and reported to them upon it. I inclose 

 you copy of their price list of 1886, still later, in which you will 

 see that "zirconium oxide" still appears without qualification ; 

 and I also forward th'^ original bottle and label which I received 

 from them — the latter you will perceive is " pure zirconia." 

 The correspondence, if sent you in full, will bear out all the 

 details above. 



At the same time I would say that I had not the least idea of 

 impugning in any way Messrs. Hopkin and Williams. I simply 

 pointed out, as reference will show, the generally unsatisfactory 

 character of samples considered commercially "pure " (one never 

 expects ordinary purchased articles " pure" in any other sense) 

 for one special purpose, and I much regret that their letter 

 necessitates this correction. Lewis Wright. 



P. S. — I am sorry to add that my previous letter has not 

 elicited any very satisfactory information, or real aid towards the 

 desired object. I learn from Mr. Cottrell that Du Motay's 

 cylinders were unquestionably more durable than any prepared 

 since, even with the aid of Prof. Maskelyne. But I am as 

 unable as ever to come across one, or to find exactly how the 

 material was prepared, or what light it gave in comparison with 

 limes. 



THE JUBILEE. 

 II. 

 ■\ 1 ZE have already referred to some aspects of the Jubilee 

 ^^ which have a special relation to science, and we 

 shall soon have occasion to return to the subject. In 

 the meantime we reprint from the Times an admirable 

 passage which presents a striking confirmation of the 

 opinions we have expressed as to the true place of science 

 in the history of the past fifty years. The passage is from 

 the " Jubilee Retrospect " which appeared in the Tiines 

 on Tuesday last : — 



" The keynote of the \'ictorian era is the development of 

 scientific research, the concomitant growth of practical 

 invention, and the expansion of industry which these have 

 brought about. Other ages have been fruitful of profound 

 scientific conceptions, or have been illustrated by great 

 inventions and discoveries, but it would be difficult to 

 point to any half-century in the history of the world 

 in which equal progress in speculative science has been 

 combined with anything approaching to the magnitude, 

 variety, and importance of the applications of science to 

 practical ends which distinguish the present reign. It is as 

 true to-day as at any former period that nothing great can 

 be done in pure science save by men who make the dis- 

 covery of truth the sole aim of their efforts, and who 

 prize no other reward. But it is no less true that abstract 

 and applied science go hand in hand as they never did 

 before, and that each owns enormous obhgations to the 

 other. For if the triumphs of the workshop have been 

 achieved by means of the discoveries made in the 

 laboratory, on the other hand the laboratory depends 

 for every step of its advance upon the technical skill and 

 hitherto unrivalled precision of the workshop. Physical 

 science has reached a stage at which the verification of 

 its hypotheses and the supply of new data for its specula- 



tions demand appliances of extraordinary excellence, and 

 in many cases a collation of experience and experiment 

 which nothing but the practical inventions of the age 

 could render possible. It is doubtless to the co-ordina- 

 tion of the two forms of intellectual activity that we owe 

 the rapidity of recent advance. An unprecedentedly large 

 army of inquirers has simultaneously pushed the inter- 

 rogation of nature in a thousand directions, and has 

 attained unprecedented results. But beside them has 

 been working an army larger, and equally keen, of men^ 

 eagerly seeking to utilize for practical ends every crumb 

 of available information, and giving to scientific ideas a 

 concrete application which often forms the starting-point 

 for new processes of scientific induction. 



" The fundamental conceptions of the material universe 

 entertained by educated men have been revolutionized 

 during the last fifty years. The simple atomic theory ot 

 the older chemistry has given place to a molecular 

 theory, which itself has undergone considerable develop- 

 ment. The outlines of the elements which the older 

 chemistry accepted as an ultimate analysis are melting 

 under the gaze of the spectroscopist, who across the haze 

 of their wavering figures catches glimpses of a simple 

 primal matter. The evolution of matter is, however, like 

 the evolution of living forms, a philosophical conception 

 which must always rest rather upon the general necessi- 

 ties of thought than upon actual experiment. The im- 

 mutability of certain forms of matter in all the conditions 

 that we can devise or have any experience of is as abso- 

 lute as the persistence of specific types in the animal or 

 vegetable kingdom. The most refractory substances 

 have been vaporized in the electric arc, and the most 

 attenuated gases have assumed the solid form under the 

 combined influence of intense cold and enormous pressure. 

 But we have made no nearer approach to actual evidence 

 either of material evolution or of the complexity of the so- 

 called elements than may be inferred from certain spectro- 

 scopic observations of the sun and some experiments 

 tending to show that in some cases we have confounded 

 two or more very similar elements under one name. 

 Apart, however, from these abstruse speculations, the 

 whole tendency of physical and chemical investigation has 

 been to bridge the gulf formerly fixed between molar and 

 molecular motion and between chemical and mechanical 

 force. There is an obvious interdependence between this 

 scientific movement and the doctrine of the conservation of 

 energy, which is one of the main philosophicalachievements 

 of the epoch under discussion. According to that doctrine, 

 the total energy of any body or system of bodies is a 

 quantity as absolutely fixed and as incapable of suffering 

 either increase or diminution as the matter of which these 

 bodies are composed. Energy, like matter, may assume 

 an endless variety of forms ; but the force put forth by 

 the locomotive is as indestructible as the particles which 

 compose its framework or its fuel. But to balance our 

 account we have to take cognizance not only of the forces 

 of impact or pressure of which we have direct experience, 

 and conceive ourselves to have tolerably full understand- 

 ing, but also of the forces of attraction and repulsion in 

 their various forms, concerning which we as yet know 

 absolutely nothing beyond the fact of their existence as 

 inferred from their effects. To refer the whole complex 

 sum of these energies to a general law, and to deal with 

 them on fundamental physical and mathematical prin- 

 ciples, is the aim of the physical science of to-day. Not- 

 withstanding all superficial resemblances, it stands differ- 

 entiated from the science of all past ages by the clearness 

 with which it apprehends the nature of this quest and 

 the unrivalled range of the analytical methods it has 

 brought to bear. In the domain of biology the theory of 

 evolution, first placed upon a scientific basis by the genius 

 of Darwin, is a product of the same great movement of J 

 philosophic thought which brought forth the molecular [ 

 theory of matter and the doctrine of the conservation of | 



