OF ARKANSAS. 
179 
soft dolomite, and excrements of bats or birds. 
to a fine powder, which feels soft between the fingers. 
Composition dried at 240 deg. F: 
The air-dried earth lost 1.681 per cent. of moisture at 240 deg. F. 
Matter insoluble in hydrochloric acid.-...- tenes 11.516 
Oxide of iron, phosphates of alumina, lime and 
magnesia eee weer eres Se ee ee ee 5.908 
LAME es ee ee eerie eee eae ww ees ee ee aoe Sis 92,929 
Magnesia CRATERS CASTER BWR TES RAN Grinds seee §=614,884 
Potassa Pe re ROR ORCC ROR te aM I ROE er RC Te ER ECR CRC TTR TE A 1.106 
Chl6TinG «sia ese aes 66 66 Oe Re ORO OW RRR Te 0.062 
Sulphuric DC or wi es aw ers RN AIS, WRIT ae OA GS 1.875 
ee -Gi ad ee e e ee acaeaem eines 0.973 
Carbonic acid -+.+.see.euenee Cece Se ce eT eT Te ee 88.487 
Organic matter, and loss:++++++++e+eees vee eens 2.790 
100.000 
It is very easily reduced 
Another portion of the air-dried earth was treated with distilled water, 
until fresh portions of the solvent ceased to take up any fixed matter. 
The solutions were united, evaporated to dryness, and the residue sub- 
jected 
sition: 
to analysis. 100 parts of the air-dried earth yielded 3.936 parts of 
solid, soluble matter, at 220 deg., F., which had the following compo- 
TA sae we steele aine ove er aes) eisrewiud canter rane ee Gye Siyeréars 1.013 
Magnesia Se ee ee er eee ee ee roe eee eT Ore ar 0.180 
POLASSAS oie ena tiale ea Pw si ooecgeercucey eae GGcel% Care 0.066 
OUT OBIE: 3 eo sie ae ie ol es Fisker ok 9) eseh opie ier'ec arse 0.012 
Pil pliunioweid WSs cocetad oneal tome cciaies 1.338 
Witric acid: ++ eee se er eee rev ereee oe ee ee ee 0.956 
Organic matter and waters +++ sess seer ee eeeene 0.371 
3.936 
Hence it follows, that from 100 tbs of the air-dried earth 1.791 tbs of 
nitre may be obtained, which consist of 0.956 tbs of nitric acid and 0.835 
ibs of potassa. 
No. 41. Nitre-determination, in a nitre earth, labeled “laminated nitre 
earth from a cave in Marion county.” 
100 parts of the air-dried earth were found to yield 9.892 parts of solid 
