May 16, 1902.] 



SCIENCE. 



783 



kept in mind, that it is better to know one 

 thing well than to have a smattering of 

 many and command of none. We must not 

 expect to see in each of our students a 

 Hebnholtz or a Ludwig Mond; if any of 

 them are destined for such versatility, they 

 will have little need of our poor instruction. 

 One solution of the time problem, then, 

 is to insist that enough time must be 

 granted, and all extraneous matter reduced 

 to a minimum. By the same token, how- 

 ever, it behooves us as conscientious chem- 

 ists to do our best to shorten the time re- 

 quired for our own subject — for the benefit 

 of the student, it might be observed, not 

 for the benefit of the coUege faculty. By 

 the aid of one further heresy, I feel able 

 to indicate where an important saving of 

 valuable time may be accomplished. I 

 would abolish from the curriculum the 

 study of qualitative analysis, the arch- type 

 of anachronisms. We owe a tender feeling 

 to the kindly nurse who brought us up 

 carefully, and taught us the dark ways and 

 vain tricks of the phosphates; but our 

 nurse is old and decrepit, and no longer 

 able to guide the toddling steps of the 

 beginner. It wiU not be difiicult to prove 

 this. The study of qualitative analysis is 

 intended to give knowledge of a useful art, 

 and specific exercise in chemical thinking. 

 It achieves neither purpose. 



SYSTEMATIC QUALITATIVE ANALYSIS AS A 

 USELESS ART. 



The problem of systematic qualitative 

 analysis as taught in our schools is to 

 recognize all the ingredients of a given 

 mixture. As a matter of fact, however, how 

 much of this art have we achieved? We 

 are able to recognize a limited number of 

 inorganic acids and bases under special cir- 

 cumstances; and the instructor must exer- 

 cise great self-restraint not to make his un- 

 knowns 'too hard.' As for the rarer acids 

 and earths, to say nothing of the vast bulk 



of organic compounds, as well as for the 

 commoner acids and bases in the presence 

 of these latter substances, we must admit 

 our inability to follow any comprehensive 

 'scheme' of analysis. The analysis of such 

 mixtures resolves itself into a series of 

 special tests, and our only check upon the 

 correctness of the analysis comes through 

 the quantitative necessity of finding one 

 hundred per cent, of the ingredients. 

 This limitation is clearly recognized by the 

 professional analyst. Thus the chemists of 

 the U. S. Geological Survey never carry out 

 qualitative analyses of the rocks they in- 

 vestigate; they assume that all of some 

 twenty or thirty ions are or may be present, 

 and check the absence of any one during 

 the progress of the quantitative analysis. 

 Nor do they undertake to analyze one 

 single sample for all of these thirty in- 

 gredients; two or more possible ones con- 

 stitute a group that is examined by itself, 

 without reference to the other contents. 

 Again, the analyst is seldom, if ever, called 

 upon to make a complete analysis of an 

 absolutely unknown brew ; on the contrary, 

 he is usually asked to estimate some two or 

 three ingredients, whose presence is either 

 known or whose absence is to be demon- 

 strated. The assayer never makes other 

 than a quantitative analysis of gold and 

 silver ores. For the food analyst, all is 

 grist that comes to his mill— moisture, fats, 

 carbohydrates, proteids and ash. 



Where then is our boasted art of qualita- 

 tive analysis? And where the need of 

 dragging every chemist through the weari- 

 some unknowns, so fearfully and wonder- 

 fully made, the like of which man never 

 saw before nor will again? Why spend 

 from two hundred to four hundred valu- 

 able hours to teach an art which does not 

 exist ? At the same time, it will be objected, 

 the numerous qualitative tests referred to 

 must be learned, and as well this way as 

 any other. Not so; the important qualita- 



