Mat 11, 1906.] 



SCIENCE. 



733 



the science of chemistry to the ai't of detect- 

 ing and separating acids and bases. In 

 their over-ardor for brevity and tabulated 

 schemes, they have emphasized the em- 

 pirical and minimized the rational aspect 

 of the subject, to its detriment as a factor 

 in liberal education. The subject has a 

 peculiar virtue if taught with the end in 

 view that it is not technical but pure chem- 

 istry. By devoting periodical hours to the 

 interpretation of the chemistry involved, 

 no branch of the science offers such delight- 

 ful and profitable employment to students. 

 I am aware that my view may possibly 

 be regarded as old-fashioned, and that there 

 is an effort to displace this subject from 

 the college curriculum. Dr. Arthur Lach- 

 man, in a recent address before the Amer- 

 ican Chemical Society, referring to quali- 

 tative analysis, said: "The chemists of the 

 U. S. Geological Survey never carry out 

 qualitative analyses of the rocks they in- 

 vestigate. * * * 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 qualitative 

 analysis?" Evidently the speaker has 

 misinterpreted or forgotten the aim and 

 genius of qualitative analysis. As an art 

 it is useful only as a handmaid to the 

 science. It is not technical chemistry, and 

 I doubt whether Liebig or Fresenius ever 

 considered it in that light. The mineral 

 analyst does not rethresh old straw by in- 

 vestigating the constitution of the positive 

 and negative ions he discovers. This he 

 learned in general chemistry. Nor does 

 he waste his time in making a qualitative 

 analysis of the average specimen; for ex- 

 perience has taught chemists that most 

 minerals are composed of only a few basic 

 and acid radicals. The argument for the 

 condemnation of qualitative analysis would 



apply with equal force to general chem- 

 istry. 



The object of qualitative analysis is not 

 so much the detection of certain ions in 

 'unknowns,' but rather a systematic study 

 of the chemistry involved in a well selected 

 and progressive set of facts. I use the 

 word 'progressive' advisedly, for though 

 the arrangement is not that prescribed by 

 Mendelejeff, it is the most practicable 

 known. Nor do we follow the periodic 

 table in the study of general chemistry, 

 for the apparent reason that oxygen, 

 hydrogen, nitrogen and chlorine are more 

 accessible and tractable than either lithium 

 at the one end, or flu6rine at the other end 

 of the table. 



5. What number of hours do you devote 

 to qualitative analysis? 



The average time calculated from these 

 replies is six hours a week for one term or 

 semester. I am glad to learn that there 

 seems to be no desire nor expectation of 

 limiting or abandoning qualitative analysis. 



6. What number of hours do you devote 

 to quantitative analysis of typical com- 

 pounds before attempting technical anal- 

 ysis? 



The language here is somewhat obscure, 

 but as yet I am unable to formulate a 

 sentence more clearly expressing my 

 thought. Hardly any two authors or 

 teachers would give identical lists of typ- 

 ical compounds for courses in quantitative 

 analysis; though probably all would in- 

 clude in their lists a dozen or more common 

 types. 



It is not surprising that a great diversity 

 of opinion and practise is shown in these 

 replies. After all, the desideratum is a 

 thorough drill in gTavimetrie and volu- 

 metric methods. Familiarity and practise 

 with the balance and other essential appa- 

 ratus, including calibration of graduates 

 and preparation of reagents, are funda- 



