456 Hutchins and Hold-en — Elements in the Sun. 



Each line is reversed four times, which increases the difficulty 

 of locating them exactly. 4048*35 seems to agree with a solar 

 line. The solar line near 4044-5 is very faint, and it is next 

 to impossible to decide the question of an agreement. 



Lithium. — The blue line of lithium presents a curious case. 

 The very broad and nebulous line has a rather sharp reversal 

 near the center, and somewhat toward the lower edge a broader 

 and less clearly defined reversal. Both these reversals agree 

 with solar lines at 4602'5 and 4603-2. It is possible that one 

 of the reversals may be due to the presence of some other sub- 

 stance, say calcium ; but if that were true, it would seem that 

 both reversals would be nearly, if not quite, obliterated. Fur- 

 ther experiment may clear the matter up. 4603'2 is given to 

 iron by Thalen. 



Platinum. — As far as we can learn, no evidence has hitherto 

 been offered to show the occurrence of this metal in the solar 

 atmosphere. We were somewhat surprised, therefore, upon 

 meeting with coincidences. Between 4250 and 4950 we find 

 64 lines of platinum, sixteen of which agree with solar lines. 

 The latter are at the following places : — 



4291-10 4481-85 



4392-00 (Thalen 4389-4) 4552-80 (Thalen 4551-8) 



4430-40 4560-30 



4435-20 4580-80 



4440-70 4852-90 (Thalen 4851-5) 



4445-75 (Thalen 4442-0) 4857*70 



4448-05 4899-00 



4455-00 4932-40 



We have taken all possible care to make this statement ac- 

 curate, and to admit no lines about which there seems to be 

 any question. There are seven other lines not included in the 

 list, the probability of agreement of which is at least as good as 

 that upon which potassium is admitted. 



In all these experiments everything has been done to bring 

 out and show upon the photograph as much as possible. The 

 lamp, constructed for the purpose and fed by a powerful dy- 

 namo, gave an arc from a half to three-fourths of an inch long, 

 and with a long flame and so intense a heat that it could be 

 worked for but a few minutes at a time. Any one who has 

 carried out a series of experiments like this is alone competent 

 to appreciate the great labor and the endless difficulties and 

 perplexities that attend them. 



Our thanks are especially due to Dr. Wolcott GKbbs for his- 

 hearty encouragement, and for the use of valuable apparatus- 

 and chemicals. 



