July 20. 1893] 



NA TURE 



281 



phosphor-bronze, seem also susceptible of considerable further 

 development. 



"The extensive manufacture of sodium affords another 

 instance of what was formerly the mere subject of a labora- 

 tory experiment, being now conducted upon a commercial 

 scale. 



" I may here just glance at the attempts that have been made 

 to produce artificially some of the precious stones that occur in 

 nature. Rubies have been manufactured, not indeed such as 

 could rank as gems, but still such as will serve to 'jewel' 

 the pivot-holes in watches ; and though the results of 

 attempts to produce the crystallised form of carbon, which is 

 known as the diamond, have as yet had but doubtful success, 

 it does not appear to me that the prospect of producing 

 genuine diamonds under combined heat and pressure is abso- 

 lutely hopeless. 



"Another direction in which great advances have been made, 

 and in which it seems probable that there yet remains some- 

 thing to be discovered, is the grouping of the various elements 

 into small divisions, having more or less analogy the one with 

 the other, and the classification of the atomic weights in one 

 harmonious series. What is known as the Periodic Law of 

 Mendeleeff and of our own Mr. John A. R. Newlands, has sug- 

 gested the possibility that what we now know as metals or ele- 

 ments may have some at present hidden connections between 

 them, so that eventually some of them may prove to be rather 

 compound bodies than strictly elementary substances. This, 

 however, is for the chemistry of the future. 



"In organic chemistry, which has been defined to be the 

 chemistry of the hydro-carbons and their derivatives, it is, as I 

 have already observed, that the most wonderful development has 

 taken place within the last half-century. Who, for instance, in 

 1840 could have foreseen the important part that aniline was to 

 play in dyeing and colouring? It was not, I think, till 1S56 that 

 Perkins's mauve was really brought into commercial use, but 

 since that time what a rainbow of colours has been produced 

 from what would have seemed a most unpromising source! How 

 brilliant are their hues, but as yet, in many cases, alas, how 

 fugitive ! Regarded from an artistic point of view these 

 colours can hardly be esteemed an unmixed blessing ; and 

 even the fabrics of Eastern looms have not escaped their in- 

 fluence. 



" QuEE regio in terris nostri non plena coloris ? " 

 Turkey, Persia, India, and China have, I fear, in many cases, 

 sacrificed taste to cheapness, and harmony to splendour in 

 colour. It is a source of some satisfaction to know that the 

 woad with which our ancient British predecessors stained 

 their bodies is still cultivated among us for the purpose 

 of dyeing wools, even though it has acquired the name of 

 Isalis tinctoria and the colouring extract is now classed as 

 an Indigotin. 



"Among inorganic colours I may here briefly mention ultra- 

 marine, which instead of being patiently produced by the care- 

 ful treatment of lapis lazuli and sold at many shillings an ounce, 

 is now manufactured by the ton and quoted by the hundred- 

 weight. Would that the artificial colour was as fine and 

 permanent as the natural ; I have, in my own time, seen it 

 supersede smalts as a colouring matter in paper-making, and I 

 have known its use not unfrequently accompanied by the 

 abundant presence of sulphuretted hydrogen as a product of 

 its decomposition. 



"Not only colouring matters but our flavours and scents have' 

 been synthetised, though art, if superseding nature for a lime, 

 must eventually acknowledge her inferiority even in pear-drops. 

 Whatever our testhetic feelings under these circumstances may be, 

 we cannot but admire the skill and scientific energy by which 

 such results have been attained. How far 'saccharine,' one 

 of the lastest results of the chemist's ingenuity, is likely to su- 

 persede the use of ordinary sugar, is a question on which I de- 

 cline to speculate. The manufacture of our every-day sugar 

 has, hi)wever, itself undergone a complete metamorphosis within 

 the last fifty years, with the result that it is now produced at 

 what would formerly have been regarded as an absolutely im- 

 possible price. In 1840, beet-sugar was in its infancy, and such 

 has been the improvement in the growth of the beet and the 

 process of manufacture that nearly twice the weight of sugar is 

 now produced from a ton of beetroot as there was at that date. 

 In the production of cane-sugar also immense economies have 

 been effected, especially in the process of evaporation. The 

 study of the effects of saccharine solutions on the polarisation 

 NO. 1238. VOL. 48] 



of light, and our acquaintance with the distinctions between 

 dextrose and Ifevulose, and of the conversion of starch into 

 sugar, all come within comparatively modern times. 



"Much of our knowledge of the mysterious processes of fermen- 

 tation is also of recent date, and it is in connection with these 

 processes that the chemist finds himself hrought into close con- 

 tact with the botanist and the physiologist. 



"Whatever suspicions Leeuwenhoek and the early microscopies 

 may have had with regard to the vegetable character of yeast- 

 cells, and however clearly Cagniard de Latour and Schwann 

 may have established its plant-like nature and its connection 

 with fermentation, it was not until Pasteur's researches from 

 185710 1861 that the true character of the yeast-plant, and of 

 other microorganisms which lie at the base of most fermen- 

 tative processes, can be said to have been absolutely demon- 

 strated. The beneficial effect of his inquiries, and of his methods 

 of obtaining a pure cultivation of yeast, is universally recognised, 

 and has reacted in the most remarkable manner on the brew- 

 ing industry. 



"But M. Pasteur's researches have also led to much wider 

 results, as it has been mainly in consequence of his careful 

 observations that the wonderful influence for good or for evil of 

 organisms so minute as in some cases almost to defy the power 

 of the microscope, has now been so fully recognised. The germ- 

 theory of the origin of many diseases meets with much more 

 general acceptance than if did but a few years ago ; and though 

 the bacilli and bacteria which are characteristic of some virulent 

 diseases, such as anthrax, are only agents in certain fermen- 

 tative processes by which poisonous matters are engendered, 

 their existence and character seem to be placed beyond all 

 doubt. The process of obtaining immunity from the action of 

 these poisons by the gradual introduction of the virus into the 

 animal system, thus rendering it insusceptible of receiving 

 further injury from the same poison, has been successfully 

 introduced, both among men and beasts, and hydrophobia and 

 anthrax have been successfully combated. 



"A recognition of the influence of germs has led to the intro- 

 duction into surgery of that antiseptic system of treatment with 

 which the name of Lister will always be .associated, and which 

 has done so much to diminish suffering and preserve life. While 

 upon this topic I may just allude to another instance in which 

 chemistry has come to the assistance of medical science, I mean 

 in the production and investigation of those anaesthetic agents 

 which play so important a part in modern surgery, and which 

 have done so much to alleviate human suffering. 



" But while the ferments produced by micro-organisms are on 

 the one hand so perniciou>, it is very doubtful whether, on ihe 

 other, they are not equally tieneficial, if it be really the case 

 that such processes as digestion are in a great measure due to 

 their action. How far the nitrification of the soil may be due 

 to micro-organisms is a question not yet absolutely solved, 

 though strong presumption has been raised of their being, at 

 all events, potent factors in the case. 



" Now that so many diseases have been traced to pathogenic 

 organisms which are constantly present in water contaminated 

 by sewage, the question of the vitality of these organisms and 

 their germs has been rightly regarded as one of great public im- 

 portauce, andthe Royal .Society, in conjunction with the London 

 County Council, has instituted an investigation into it, which is 

 being diligently prosecuted both from the botanical and the 

 chemical points of view. The remarkable power of light, 

 whether that of the sun or electric, in sterilising the germs of 

 .■^ome micro-organisms, already to some extent previously known, 

 has been conclusively demonstrated by Prof. Marshall Ward. 



" .Much has been done of late years by chemists towards the 

 purification of sewage with ihe vieiv of rendering the effluents 

 from the uliimate drains of our large municipalities as innocuous 

 as possible, and the results obtained have been in many instances 

 satisfactory. They would, no doubt, have been even more so 

 had not the imperative demands of economy limited the cost. 

 Still, whatever may be done, I am inclined to think that there 

 is much truth in the metrical abstract of a paper read some 

 years ago before the Royal Society : — 



"Sewage, however disinfected, 

 Is not from ill results jjrotected : 

 'Ihtugli made to all appearance pure. 

 It stili remains not safe, but sewer." 



"I will not attempt to discuss the important question of the dis- 

 posal of the sewage of our great towns, but to many it will appear 

 as somewhat of a disgrace to our powers of applying chemical 



