236 COSMOGONIC HYPOTHESES. 



Ramsay. — " Elements and Electrons," 191 2. 



" Cordite, the explosive powder used for our artillery, evolves 

 1,253 calories per gram. . . Radium, 2,800,000,000 calories." 

 ScHWARz. E. H. L. — Causal Geology, 1910. 



The ideas awakened by this original anci suggestive book 

 gave rise to the present paper. 



ADDENDUM. 



Since the above was written, a paper on the " Structure of 

 the Universe," by Professor J. C. Kapteyn, has appeared in 

 Scieiitia, Vol. XIV. He writes (page 352) : 



Must we conclude that the nebuhe are not the birthphxce of stars? It 

 may seem so. Let us not conchide too hastily, however. There are nebula? 



and nebul?e Herschel saw in them (the planetary nebulae) a 



likeness to what, according to Laplace's cosmogony, must have been the 

 primitive aspect of our solar system, and he thus imagined that they must 



be worlds in statu nasccnti Such a view now seems untenable. 



The planetary nebulae cannot be the birthplace of the stars. . . As I 

 have just now said, there is one nebula for which the radial velocity has 

 been determined, which is not planetary. It is the well-known Orion 

 nebula belonging to the class of the irregular nebulie. May not these 

 irregular nebulae give birth to the stars?" 



On page 353 he writes : 



How have to explain the fact that the internal velocity of stars 

 increases steadily as they grow older? The astronomer who, in his 

 study of the motion of the heavenly bodies has found hardly a trace of 

 any other force than gravitation, will naturally turn to gravitation for 



such an explanation If it be true that mutual attraction of the 



stars has generated such an enormous amount of internal motion in the 

 time needed by the stars for their evolution from helium to second- or 

 third-type stars, how have we to explain the fact that we find the same 

 matter nearly at rest at the first stage of stellar life? .... WhaJ; 

 may be the explanation ? Is there really no gravitation in primordial 

 matter? I have no solution to ofifer?" 



Although the whole of Professor Kapteyn 's article should be 

 read, the above extracts are those which chiefly concern my argu- 

 ment. The first extract shows that in F^rofessor Kapteyn's 

 opinion a great part of the Nebular Hypothesis must be thrown 

 overboard, in that it is on!}- the large irregular nebulae such as 

 that of Orion that we must now look to as forming the matter 

 out of which stars are formed. This, however, svipplies no 

 answer to the pressing question. Whence comes the energy which 

 transmits light elemetits into heavy elements? In the second 

 extract given. Professor Kapteyn is very sure that tlie order of 

 evolution is (i) irregular nebulae, (2) helium stars, (3) hydro- 

 gen stars, (4) metallic line stars, (5) absorption band stars, and 

 mainly because the velocities of stars increase in this order. The 

 remarkable discovery that stellar velocity depends on spectral 

 type was made independently and by ditferent methods of attack 

 almost simultaneously by two American astronomers. Dr. Camp- 

 bell, of the Lick Observatory, and the late Lewis l)Oss. The 

 following little table is taken from Lick Observatory Bulletin 

 No. 196, 191 1, -A^pril 20: — 



