Maech 18, 1898.] 



SGIENGK 



369 



present subject. There is no doubt that 

 the electric telegraph was a slow-growth 

 invention, with a view to pecuniary and 

 other advantage, being ever ready to lay 

 hold of each scientific discovery and try to 

 turn it to account. The question who first 

 conceived the idea can never be satisfac- 

 torily answered. 



After 1840 there is little to record of a 

 purely electrical character bearing only on 

 telegraphy, but there have been many very 

 ingenious mechanical contrivances intro- 

 duced for recording signals, for reproducing 

 pictures and handwriting and for printing, 

 for duplexing, quadruplexing and multi- 

 plexing telegraph lines, for increasing the 

 rate of signaling and in many ways increas- 

 ing the expedition with which messages can 

 be sent. Of course, the success of many of 

 these contrivances, and even their invention, 

 depended upon an increased knowledge of 

 the laws of electricity and magnetism. For 

 example, effective duplexing, quadruplex- 

 ing, etc., depends on a proper understanding 

 of the electrostatic capacity of the line, and 

 this was not understood properly until the 

 mathematical investigations of Thomson 

 and others cleared the matter. For the im- 

 petus towards discovery in this direction 

 again we are largely indebted to telegraphy, 

 for much of that class of work was sug- 

 gested by the difficulties encountered in 

 signalling through long submarine cables. 



The invention of the telephone is fast be- 

 coming ancient history, and yet it will al- 

 ways mark one of the greatest of the use- 

 ful applications of electricity. It does not 

 call for more than a passing remark here, 

 because electro-magnetically it is all in 

 Faraday's and Henry's papers. 



The radiophone should be mentioned be- 

 cause it marks the application of the dis- 

 covery, by May and Smith, of the effect of 

 light on the resistance of selenium. This 

 effect has since been found in the case of a 

 large number of other substances, but it is 



still an interesting field for research. A 



number of experiments on this subject have 



been associated with attempts to make 



things visible at a distance. No doubt it 



will ultimately be possible not only to talk 



to a distant party, but also to see the party 



talked to, and thus, as it were, look the party 



with whom you are conversing in the eye. 



Thomas Gray. 



Rose Polytechnic Institute. 



(To he concluded.') 



THE PROVINCE AND PR0BLE3IS OF PLANT 

 PHYSIOLOGY* 



The exploitation and survey of the flora 

 of our continent is a task of such tremen- 

 dous magnitude that it has consumed the 

 greater portion of the energy of American 

 botanists until within a few years of the 

 present time. The constantly increasing 

 number of workers attracted to the subject 

 has made possible not only a more thorough 

 organization of the interests of taxonomic 

 botany, but has also permitted a great deal 

 of attention to questions of general morphol- 

 ogy and cytology. "Within the last decade 

 an awakening interest has been shown in 

 subjects in the physiology of plants. This 

 interest has been manifested by the intro- 

 duction of physiological matter in the text- 

 books on botany, by the organization of 

 courses of instruction in this branch in 

 some of the more prominent colleges and 

 universities, and by the accomplishment of 

 investigations of more or less importance. 



Any subject is liable to misconception 

 and misapprehension during the earlier 

 stages of its introduction into any country, 

 and plant-physiology in America is no ex- 

 ception to the probability. 



A misapprehension of a subject is likely 

 to be followed by a perversion of the 

 facilities devoted to it, the neglect of its 



* Read before the Minnesota Academy of Science, 

 December 30, 1897. 



