81. Carbonate of soda (trona), thick-fibrous foliated, in crusts of the thickness of one-fourth to one-third of an inch, indistinctly crystallized on the upper surface. “From the trona lakes in Wady Trona.”
82. The same, studded on the upper surface with small limpid cubical crystals of muriate of soda. From ditto.
83. Carbonate of soda, of yellowish and greenish-grey colour, in masses with diverging radiated fracture. Kanem?
84. A rolled piece of nearly compact brown ironstone. “Upper strata from Aghadem to the southward of El Wahr.”
85. Compact brown ironstone, of dark brown colour; an irregularly tubercular nodule, with surface, particularly that of the old fractural planes, glossy, the recent fracture exhibiting a dull earthy surface. “From plains to the southward of Bonjem.”
86. Compact brown ironstone, of deep chesnut-brown colour, in rounded oblong pieces of from one-half to upwards of an inch in diameter, the whole glossy as if varnished; fracture even, earthy. From ditto?
87. Fragment of compact brown ironstone, mixed with much quartzy matter. Wady Kawar and Aghadem.
88. Massive and granular brown ironstone, mixed with much yellow iron ochre and sand. “In loose masses or crusts, on the top of the ridges between Sockatoo and Kashna, and on the low hills around Sockatoo.”
89. Fragments of clayey brown ironstone with ochrey nodules. “Wady Shiati hills.”
90. A mass, mixed, of brown ironstone and red and yellow iron ochre. “From the soil of Wady Sandalion, Tuarick country.”