Journal of the Franklin InstituteVolume 93, Issue 3, March 1872, Page 160Editorial CorrespondenceAuthor links open overlay panelShow moreShareCitehttps://doi.org/10.1016/0016-0032(72)90561-3Get rights and contentReferences (0)Cited by (0)View full textCopyright © 1872 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.