August 19, 1004.] 



SCIENCE. 



251 



theless are large enough to reflect and also to 

 polarize light. These luminescent solutions 

 are called pseudo-solutions. In true colloidal 

 solutions the maximum diameter of the par- 

 ticles was found to be 5 ix/x, that is about ten 

 times as large as the mean diameter of mole- 

 cules. This raises the question as to whether 

 there is any real boundary between true solu- 

 tions and colloidal solutions. If not, sub- 

 stances with very large molecular weight ought 

 to give evidence when in solution of interrup- 

 tion of a ray of light similar to that of col- 

 loidal solutions. It was found that water 

 rendered optically clear was not affected by 

 the addition of urea, acetamid, methyl or ethyl 

 alcohol, but light reflected vertically from a 

 solution of saccharose (mol. wt. 342) and 

 raffinose (mol. wt. 504) was polarized. Strong 

 luminescence was given by a solution of phos- 

 phomolybdic acid. The authors consider it 

 probable that with sufiiciently strong source 

 of light even substances of lower molecular 

 weight would show reflection from the dis- 

 solved molecules. 



The second paper, whose co-author is R. P. 

 Van Calcar, is on the effect of centrifugal 

 force on dissolved substances. The solutions 

 were submitted to a centrifugal force 400 times 

 that of gravity. Under these conditions a 

 one fifth normal solution of potassium iodid 

 showed after three hours pure water in the 

 upper portion, a concentration of 0.1 normal 

 immediately below, 0.32 normal at the top of 

 the lower half and one fourth normal at the 

 bottom. In a number of other cases solutions 

 became manifestly more concentrated at the 

 periphery. In a solution containing 8.78 per 

 cent, of sodium sulfate after five hours rota- 

 tion a considerable amount of Glauber's salts, 

 Na.SOj, lOHjO, had crystallized out and the 

 remaining solution contained only 5.54 per 

 cent, of sodium sulfate. These results are 

 the more important, as it has generally been 

 accepted since the negative experiments of 

 Gay-Lussac, that the molecules in a true solu- 

 tion were unaffected by gravity, and hence 

 were in a different state from those in colloidal 

 or pseudo solutions, and it also confirms from 

 a different point of view the results of Lobry 

 de Bruyn and Wolff described above. 



J. L. H. 



SOCIAL AND ECONOMIC SCIENCE. 



UNIVERSITY COMPETITION FOR GRADUATE 

 STUDENTS. 



In his latest annual report President Had- 

 ley, of Yale, calls attention to this phase of 

 university effort in the following statement: 

 " For some time past many of the universities 

 of the country have been engaged in a rather 

 unfortunate competition for graduate students. 

 There was in certain quarters a tendency to 

 measure the success and usefulness of an insti- 

 tution by the numbers enrolled for graduate 

 study. Under the influence of these ideas 

 there has been a strong tendency to treat grad- 

 uate students in the present generation as 

 divinity students were treated a generation 

 ago — giving them not only free tuition, but a 

 great many other pecuniary inducements to 

 pursue special studies for the degree of doctor 

 of philosophy. 



" This course of action involves an inver- 

 sion of the true order of things. If you have 

 real interest in science and literature you will 

 probably have a number of men pursuing 

 courses for the degree of doctor of philosophy; 

 but it by no means follows that if you have a 

 number of men pursuing courses for the doc- 

 torate of philosophy you will have a corre- 

 sponding amount of interest in science and 

 literature. On the contrary, this attempt to 

 subsidize graduate students too often increases 

 numbers at the expense of quality; and so far 

 as it does this is bad. A good graduate stu- 

 dent is about the best man that we have in the 

 university; a poor graduate student is about 

 the worst man. The same conditions which 

 allow a man to rise above the average of his 

 fellows if he has the ability and stimulus in 

 himself allow him to fall below his fellows if 

 he has not that ability and stimulus. * * * 

 If the numbers of the graduate students in- 

 crease instead of diminish it will be a source 

 of congratulation; but it will be far better to 

 submit to some loss of numbers than to con- 

 tinue a form of competition which is prejudi- 

 cial to the quality of the students, wasteful 

 of the resources of the university, and based 

 upon an imperfect appreciation of the pur- 

 poses and scope of university work. A uni- 



