664 



SCIENCE 



[N. S. Vol. XLIV. No. 1141 



with which mankind is concerned, and that 

 the energy which supplies the world to-day 

 is being derived largely from a rapidly di- 

 minishing supply of fuel stored up in the 

 past, it is evident that atomic structure is 

 one of the most fundamental problems with 

 which science is concerned. 



I know it would be presumptive to as- 

 sume that we shall sometimes be able to 

 utilize the energy which is stored up in the 

 atom, and, on the other hand, it would be 

 equally presumptive to assume that the 

 atom is the barrier beyond which science 

 can not go. The history of science contains 

 numerous examples of these barriers which 

 have been placed by scientists themselves, 

 and which in many cases have fallen before 

 the conquest of these same scientists. 

 Maxwell said the "atom is incapable of 

 growth or decay, of generation or destruc- 

 tion." We now know that certain atoms 

 are disintegrating, and new atoms forming 

 continually. Less than a century ago scien- 

 tists assumed that a "vital force" was 

 essential in the formation of organic com- 

 pounds. To-day thousands of such com- 

 pounds are being synthesized in the labora- 

 tory, and many useful products are being 

 made which, so far as known, the "vital 

 force" has never produced. When Hertz 

 succeeded in producing electromagnetic 

 waves which are now the basis of wireless 

 telegraphy and telephony, he thought it 

 would be impossible to make use of such 

 waves to transmit signals to any great dis- 

 tance. And so on, the unknown and ap- 

 parently the unknowable of one generation 

 may become the commonplace knowledge 

 of the next. We do not know to what ex- 

 tent we shall be able to solve the mysteries 

 . of the atom, and we are unable to even pre- 

 dict the consequences of such a discovery. 

 We know that the problem is beset with al- 

 most insurmountable difficulties, and that 

 our knowledge on the subject can never 

 reach finality. 



The interior of the atom is the common 

 ground where chemistry and physics meet, 

 and there is probably no problem before 

 the scientific world to-day that offers 

 greater difficulty or promises greater re- 

 ward than that of determining the nature 

 and arrangement of the constituents of the 

 atom, and the laws which govern their mo- 

 tion. The discoveries already made in this 

 direction have broadened the range of sci- 

 entific research, and advanced our knowl- 

 edge one step farther into the mysteries of 

 nature; and it is largely the mastery of 

 man over the laws of nature which marks 

 the progress of the world. 



WlLLETT L. HaEDIN" 



Los Angeles, Calif. 



ON THE UTILITY OF FIELD LABELS 

 IN HERBARIUM PRACTISE 



Routine technique in ordinary herbarium 

 practise has made little advance for many 

 years, in sharp contrast to the highly special- 

 ized technique in most other fields of botan- 

 ical work. It is true that no revolutionary 

 changes are to be expected in herbarium meth- 

 ods, yet the author is convinced that some 

 changes are urgently needed in order that the 

 great herbaria now so rapidly being built up 

 in this and in other countries shall be more 

 generally useful than they are to-day. 



It is perhaps a survival of the Linnean idea 

 that the name of the plant was the im- 

 portant thing to record on the specimen, and 

 that all other data were secondary, that is re- 

 flected in modern herbarium practise. We 

 have advanced, however, to the point where it 

 is conceded by all botanists that the conven- 

 tional data, geographic locality, collector and 

 date of collection must be added to each speci- 

 men, yet many botanists and collectors do 

 not realize the vital necessity of recording in 

 a form that will be available to other workers 

 essential data regarding the plant itself. The 

 result is that the chief value of most large 

 herbaria, aside from supplying material by 

 which the limits of variation may be deter- 

 mined, or the limits of species decided, and in 



