74 



NA TURE 



{May 25, 1876 



But not alone on the ground of utility and incentive to 

 the further useful discovery of technical applications would 

 I plead for the establishment of national museums of 

 chemical preparations ; such collections would be of the 

 highest interest both to the student and the investigator. 

 They would call vividly before the mind the results of 

 labours which can only otherwise become known by a 

 tedious search through the transactions of learned so- 

 cieties. An intelligent study of a properly arranged col- 

 lection of artificial chemical compounds would show the 

 progressive triumph of mind over matter — not over 

 masses moved by mechanical agencies — for monuments of 

 this the engineer and the architect need only bid the in- 

 quirer, in the language of Wren's tablet, to "look around 

 him " — but over the ultimate atoms which, in these com- 

 pounds, are compelled to submit themselves to the will of 

 man, and to form new structures, seen only, in most cases, 

 by the discoverer himself, and the qualities and uses of 

 which are but very imperfectly ascertained. Nine-tenths 

 of these compounds are no better known than islands 

 which have been seen only from the deck of a ship and 

 whose position has been accurately marked upon a chart. 

 But a collection of them, if properly kept up, would repre- 

 sent the actual condition of our knowledge of chemical 

 facts, and, if properly arranged, would suggest to the ob- 

 servant student the direction of future investigation. 



I know of no other incentive to research which would 

 be more likely to call original inquirers into existence. 

 The student wishing to commence a chemical investiga- 

 tion is always confronted at the outset by the difficulty of 

 finding the boundary line between the known and the 

 unknown, and this difficulty must obviously increase from 

 year to year owing to the continued expansion of the 

 circle of knowledge. It has led to a suggestion emanating 

 from the British Association, that chemists who are inti- 

 mately acquainted with particular departments of their 

 science should suggest subjects of research for the benefit 

 of students. Much maybe said no r'oubt in favour of 

 such a scheme ; but it appears to mc that the develop- 

 ment of original talent in the young investigator would 

 be more surely promoted by giving him the means of 

 selecting for himself a subject for experimental inquiry, 

 rather than by inducing him to follow the less invigorat- 

 ing plan of working out the suggestions of others. 1 ven- 

 ture, therefore, thus prominently to call attention to thenon- 

 existence, in any country, of a museum of artificial com- 

 pounds, and to the great value, both economical, scientific, 

 and educational, which such a museum would possess. I 

 feel convinced that if such museums were established in 

 the capitals of Europe, chemical investigators throughout 

 the world would gladly contribute their new products to 

 them, and thus keep them abreast of the discoveries of 

 chemical science. 



Amongst the groups of objects in the Chemical Section, 

 not the least interesting is that which consists of Appara- 

 tus and Contrivances employed in the Generation and 

 Application of Heat. The great advances which have 

 been made in the modes of producing and applying heat 

 for chemical purposes are strikingly- conspicuous. The 

 cumbrous furnaces of the earlier operators, constructed 

 in fireproof vaults, have gradually been replaced by 

 simple and elegant contrivances, which would scarcely 

 look out of place upon a drawing-room table. The time 

 js still fresh in the recollection of many of tis, when the 

 fusion of a silicate for quantitative analysis, or the heat- 

 ing to redness of oxide of copper for the combustion of 

 an organic compound, required in each case the expend- 

 iture of much time and trouble in the lighting of a coke 

 or charcoal furnace. Now these operations are performed 

 in small gas furnaces with or without air blast. Conspic- 

 uous amongst these inventions are the gas-burners of 

 Bunsen and Hofmann, the oxy-coal gas furnaces of Deville, 

 the blast gas furnaces of Griffin, and the hot blast gas fur- 

 naces of Fletcher. Of these fundamental inventions many 



ingenious modifications for special purposes have been 

 devised, amongst which I may mention the valuable con- 

 trivances of Finkener, Mitscherlich, Wallace and Miincke. 

 The blast gas-burners of Hofmann and Bunsen, the blast 

 gas-furnaces of Deville, Griffin, and Bunsen, and the fur- 

 naces for organic analysis by Hofmann, Bunsen, Finkener, 

 Mitscherlich, and Miincke, are amongst the exhibits illus- 

 trating the application of heat in chemical operations. 



These burners and furnaces command a range of tem- 

 perature from the gentlest ignition up to the most intense 

 heat procurable by chemical means ; but the temperature 

 produced by such combinations as those of oxygen and 

 hydrogen, or oxygen and cai'bon, enormously high though 

 it be, now no longer suffices, and recourse must be had to 

 the still more intense heat of the electric discharge. The 

 electric current and the stream of sparks are now not un- 

 frequently called into requisition by the chemist, and from 

 this point of view the electric lamp and the apparatus of 

 Hofmann and others for the decomposition of gases by 

 the spark-stream must be classed with chemical furnaces. 



To apparatus for the application of heat belong the 

 various forms of water, steam, and air baths, or drying 

 closets. Convenient contrivances of this class invented 

 by Bunsen, Mitscherlich, Habermann, and Miincke, are 

 exhibited by Messrs. Warmbrunn, Ouilitz and Co., Mr. 

 Johann Lentz, and Mr. Julius Schober all of Berlin, and 

 by Mr. C. Desaga of Heidelberg. 



In the application of gas to chemical purposes, regulators 

 of pressure and temperature are often of the utmost im- 

 portance, in order that operations requiring the prolonged 

 and regular action of heat may not require the constant 

 attention of the operator. The ingenious and effective 

 contrivances of Bunsen and Kramer, for this purpose are 

 exhibited. 



Closely connected again with appliances for raising 

 temperature are those intended for its reduction — the 

 refrigerators or condensers. — The Liebig's condenser is 

 still the refrigerator almost exclusively used, but few pieces 

 of apparatus have been so much modified and refined, as 

 will be seen on comparing the original design with the 

 present construction — the final light and convenient form 

 having been given to it by my late friend Mr. B. F. 

 Duppa. Most manufacturers of chemical apparatus 

 exhibit various forms of this condenser. 



Sprengel Pumps. — Of the comparatively recent appli- 

 ances for facilitating chemical work, few can lay claim to 

 higher merit than the invention of Dr. Hermann Sprengel, 

 in the year 1865, for the production of vacua by the fall 

 of liquids in tubes ; and yet this invention remained for 

 many years dormant, until the late Master of the Mint 

 applied the mercurial pump to the extraction and collec- 

 tion of occluded gases, and Bunsen the water-pump to 

 hastening the filtration of liquids. Without the mercurial 

 pump the elements of the organic matter in potable waters 

 could not be determined, and the highly interesting results 

 which this pump has quite recently achieved in the hands 

 of Mr. Crookes, come home to every one who has seen 

 the various forms of the radiometer. 



Bunsen's application of the water-pump to filtration has 

 done much to shorten one of the most tedious and trouble- 

 some operations of gravimetrical analysis. 



Dr. Sprengel's invention has, moreover, nearly abolished 

 the use of the air-pump in chemical laboratories, and I 

 need not therefore, perhaps, bring under the special notice 

 of this section the various improvements in air-pumps 

 which are illustrated by the exhibits in the Physical 

 Section. 



Models, diagrams, appa^ attis and chemicals used in the 

 teaching of chemistry, mclude numerous exhibits of great 

 interest. It is to be regretted, however, that models and 

 plans of chemical laboratories are not more numerously 

 represented. The important improvements which have 

 been introduced of late years, and the numerous labora- 

 tories of truly palatial proportions which have been built. 



