494 G. F. Kunz—WMeteorice Tron from Arkansas. 
Note in Conclusion. 
The investigations of which the preceding pages are the 
result, are still unfinished. I have very lately observed the 
formation of another group of silver haloids quite different 
from the photosalts. The members of this new group are 
deeply colored, purple or red, not unlike the photosalts, but are 
sharply distinguished from them by very different reactions. 
The photosalts are unaffected by cold strong nitric acid; these 
new salts are by very dilute acid instantly converted into a pale 
pink substance which appears to be-a photosalt. But the most 
striking difference is in the action of ferric chloride, A strong 
sclution of this substance shows no action with the photosalts 
unless left in contact for many hours or days. But these new 
haloids are instantly converted by it into what is apparently 
light pink photosalt. 
So energetic is this action that a solution of ferric chloride 
containing one part only to a thousand of water quickly 
attacks these dark purple salts and decolorizes them. Such a 
solution might remain indefinitely in contact with the sub- 
stances I have called photosalts without affecting them. 
Other differences exist. So far as I have yet been able to 
observe these new haloids are formed pure, whereas the photo- 
salts are almost always contaminated with either free silver or 
free subsalt, or both. As yet there has been no time to fix with 
exactness their mode of formation or their properties, which I 
hope to do at a future day. 
Philadelphia, April 27, 1887. 
s 
Art. XLIX.—On the Meteoric Iron which fell near Cabin Creek, 
Johnson County, Arkansas, March 27th, 1886; by GEorGE F. 
KUNZ. 
THE Johnson County meteoric iron, the tenth whose fall has 
been observed, is of more than ordinary interest, because its 
fall is so well substantiated, because it is the second largest mass 
ever seen to fall, and again because it fell within five months 
of the date of the 9th* recorded fall, that of the Mazapil. Itis 
* This Journal, IIJ, vol. xxxiii, p. 221. This meteorite was first mentioned 
before the New York Mineralogical Club, Feb. 2d, (N. Y. Academy Science, 
March), and full details’ will be printed with plates figuring both sides of the iron, 
natural size, in the Bulletin of the National Museum. The irons whose falls have 
been recorded thus far, are: Agram, Croatia, May 26th, 1871. Charlotte, Dickson 
Co., Tenn., Aug. Ist, 1835. Braunau, Bohemia, July 14th, 1847. Tabarz, Saxony, , 
Oct. 18th, 1854, Victoria West, Africa, 1862. Nejed, Central Arabia, Spring of 
1865. Nedagolla, India, Jan. 23d, 1870. Rowton, Shropshire, England, April 20, 
1876. Mazapil, Mexico, Nov. 27th, 1885. 
[It appears questionable whether the 4th, 5th and 6th in the list should be 
included, since, so far as we are aware, no account of their fall has been pub- 
lished.—EDs. | 
