Sends copy of South America.

Will consult BS’s article in the Bulletin.

Recommends article by Daniel Sharpe ["On slaty cleavage", J. Geol. Soc. Lond. 3 (1847): 74–105].

Cites his description of thin laminae in volcanic rocks in Volcanic islands. Suggests similar process may have affected metamorphic schists.

Thanks him for offer of his book [Lehrbuch der physikalischen Geographie und Geologie (1844–7)]. Since he reads German poorly, BS should send book only if short and inexpensive.