Herbert Spencer published his famous essays on education, the battle has raged over "What knowledge is of most worth," Without venturing into the general topic, we would submit that what is done must be well done if it is to accomplish any of the advertised objectives. The progress of civilization has been marked by the steps taken to establish standards of value. In the last two decades the "standard test" has been introduced into our educational system as an aid in comparing the work in different institutions. While an examination into the merits and demerits of the standard test is beyond the scope of this brief note, it will be obvious that a "standard test" can give no information in regard to the proficiency attained in laboratory technic. It was, therefore, with the idea of encouraging the establishment of norms for laboratory performance that we undertook a detailed analysis of the achievements of students in our beginning laboratory course in chemistry. EXPERIMENTAL DATA* Comparison of grades is not very informative, for a grade is often a better indication of the metabolism of the grader than it is of the quality of work done by the gradee. We selected, rather, the actual figures obtained
A standardized method, markedly efficient, for the preparation of symmetrically substituted thioureas and thiuram disulphides from primary and secondary amines has been developed in conformity with the following equations:
Its uniformity of application to seven primary amines and to seven secondary amines has made possible a comparative study of the times required, the extent of completion of the reactions, and the effect of various substituents, in the preparation of the corresponding thioureas and thiuram‐disulphides.
The preparation and identification by quantitative analysis of five thioureas and five thiuram disulphides, not previously recorded in the literature, has been effected.
Three new unsymmetrical tri‐substituted thioureas have been prepared in conformity with the general equation, RNCS+R′R″NH → RNH. CS. NR′R″. Their identity has been established by quantitative analyses.
previous paper embodying part I of the present title1 has elicited, several comments. One writer states that he has accumulated considerable data and hopes to get it organized soon so that it may be compared with ours.A second letter states that by placing such over-emphasis on laboratory technic the student gets a narrow
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