October 18, 1895.] 



SCIENCE. 



509 



The sj'stem is simpler, clearer, saves repe- 

 tition and time (five months instead of six 

 and a half), is less burdensome to the mem- 

 orj^, and gives a fairly uniform system for 

 inorganic and organic chemistry. This in 

 itself is an advantage not to be lightly esti- 

 mated. 



The table is not to be pushed too far — one 

 must be careful not to go to lengths incap- 

 able of direct proof. The position in which 

 the elements fall should not be used as 

 having any reference to their genesis, deri- 

 vation or composition. 



As to graphic representations of the ISTat- 

 ural System, I have examined all and re- 

 jected all as unsuited to teaching the science. 

 All are open to the serious objection of car- 

 rying analogies too far, and leading the 

 student on to deductions and dreams for 

 which the chemist of to-day has no possible 

 proof. 



Take for example the pendulum oscilla- 

 tions of Spring and Reynolds, inseparably 

 connected now with Crookes' speculation 

 as to the Genesis of the Elements or take 

 Preyer's condensation-steps and genera- 

 tion pyramids, all full of this idea of the 

 genesis. Mendeleeff dismisses the idea of 

 such curves of properties as Meyer devised, 

 and there is much weight in his criticisms. 

 Such curves are, at any rate, instructive 

 only to those who are capable of reading 

 mathematics critically. 



I would counsel the use of the simple 

 table without the questionable aid of curves 

 or diagrams of any kind. 



The summing up of the whole matter is 

 this : If the Natural System is true it can- 

 not be relegated to a side place in j^our 

 teaching. It forms the basis of your entire 

 course, and unless you utilize it you are 

 occiipying a false possition and depriving 

 yourself of the most valuable aid which 

 the teacher of to-day has at his command. 

 F. P. Venable. 



University of Noeth Carolina. 



THE 8TA TUS OF THE SOLAR MAGNETIC P BOB- 

 LEU. 



A SERIES of papers has been published in 

 different journals during the past four years 

 giving a very brief account of the steps ta- 

 ken in the investigation of the general prob- 

 lem of the transference of energj^ from the 

 Sun to the Earth. It is probable that the 

 main thread of the argument may be ob- 

 scure to some readers for want of a consecu- 

 tive statement of the case, and it is there- 

 fore proposed to summarize the evidence 

 already obtained, as well as to indicate the 

 nature of the scientific questions immedi- 

 ately at hand. 



The research has been one of peculiar 

 difficulty to successfullj'- prosecute to defin- 

 ite conclusions, not because the line of 

 operations was obscure, nor on account of 

 the intricate mathematical conditions, but 

 chiefly in consequence of the looseness of 

 the phenomenon under consideration. By 

 looseness is meant the wide deviations from 

 the normal laws, whatever these may be, 

 arising from the actual spasmodic actions of 

 the sun on the one hand, and the very in- 

 direct effect of the solar energy thus gener- 

 ated upon the terrestrial, magnetic and me- 

 teorological fields, as recorded by the in- 

 struments employed in observations. This 

 is an ordinary difficulty when the ether is 

 the medium of the transference of energy 

 between masses of matter widely separated 

 in space, and in our case it is especially 

 complex by reason of the complicated na- 

 ture of the transmitter aud the receiver, 

 nameljr, the sun and the earth respectively. 

 The solution of the problem must neces- 

 sarily be by a system of approximations, in 

 which unknown terms are carried hidden 

 in the residuals during one operation, until 

 the result obtained enables a repetition of 

 the work under clearer conceptions. Also 

 the complication of terms is so great that it 

 is only by the successful treatment of an 

 enormous mass of material that the im- 



