RT Journal Article SR Electronic T1 Laboratory notes JF American Journal of Science JO Am J Sci FD American Journal of Science SP 376 OP 378 DO 10.2475/ajs.s3-7.40.376 VO s3-7 IS 40 A1 M. Carey Lea YR 1874 UL http://www.ajsonline.org/content/s3-7/40/376.abstract AB