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SCIENCE 



[N. S. Vol. XXX. No. 771 



through the solution of definite problems 

 suggested by the analytical operations 

 themselves. The lectures should be very 

 largely experimental, and might consider, 

 among other things, the logical sequence of 

 the most essential facts which led to the 

 proposal of the theory of solution; the ex- 

 perimental basis for the hypothesis of ions 

 and the theory of electrolytic dissociation; 

 the significance and application of the laws 

 of chemical equilibrium (homogeneous and 

 heterogeneous) with illustrations chosen 

 from the wealth of material furnished by 

 analytical processes. 



As an outcome of the discussion of the 

 nature of chemical equilibrium, the stu- 

 dent will be in a position to consider cer- 

 tain topics— the methods of deriving dis- 

 sociation constants may be presented 

 briefly, and the value to the analyst of a 

 knowledge of these constants may be 

 dwelt upon at some length ; the problem of 

 the solubility product may properly take 

 some time, since there will be little diffi- 

 culty in making its value and application 

 plain by selected experiments, many of 

 which the student himself may perform in 

 the laboratory; the study of complex ions 

 and their stability constants will furnish 

 abundance of material for experiment and 

 discussion. These few main points may 

 serve to suggest the changes so greatly to 

 be desired in the teaching of this division 

 of chemistry in the colleges. 



It is here that the subject matter of ele- 

 mentary physical chemistry and analytical 

 chemistry overlap, and the one takes from 

 the other certain chapters which may be of 

 practical service to it in the successful 

 elucidation of its particular problems. By 

 this overlapping, qualitative analysis has 

 ceased to be governed largely by rule of 

 thumb, and has passed into an organized 

 and orderly subject with that real "scien- 

 tific foundation" prophetically announced 

 by Ostwald a number of years ago. 



What I have said concerning qualitative 

 analysis applies with equal force to quanti- 

 tative analysis. It must be admitted that 

 the laboratory art is exceedingly intricate 

 and varied, and should be thoroughly 

 learned. When, however, the student is 

 permitted to devote his entire time to it, 

 except for interruption by a single weekly 

 recitation on problems, the loss to him is 

 irreparable. 



As regards elementary physical chemis- 

 try there is little to say, since there are 

 very few colleges which give any definite 

 course in this subject, unless a course in 

 theoretical chemistry is made to serve this 

 purpose also; but it is doubtful whether 

 the courses given under this title deserve to 

 be classed as physical chemistry in the 

 present sense of the term. There can be no 

 question as to the desirability of such a 

 course as a part of the college curriculum ; 

 its appearance in certain college announce- 

 ments gives us hope that others may follow. 



The recent changes which I have men- 

 tioned in connection with the teaching of 

 analytical chemistry have gradually found 

 an entrance into the methods employed in 

 some institutions, and may be looked upon 

 as fairly established in many quarters. 

 With the teaching of organic chemistry 

 the case is different. I believe that this 

 division of chemistry is in a transition 

 stage with respect to the content and char- 

 acter of the subject matter presented in 

 the elementary course. 



It is generally conceded that qualitative 

 analysis ought to be the course which 

 should follow logically upon the heels of 

 the elementary course. In fact, this prac- 

 tise has been in A'ogue for so many years, 

 and has been advocated by so many famous 

 teachers that it has come to be looked upon 

 as a matter of necessity, rather than 

 choice. This, however, is by no means the 

 case. For many years, organic chemistry 

 has formed rather a mature part of a stu- 



