Perhaps just a word in explanation of the title of this paper will not be amiss. We speak of Portland Cement as possessing life. We do this because the duration of its existence as Portland Cement is measurable. In contradistinction we might speak of a material such as the Sioux Falls Quartzite as being dead, since no appreciable change takes place in the body of this Quartzite, all of the elements of the Quartzite being practically at a state of rest and resisting all disintegration by the ordinary weathering agencies. Perhaps our distinction may be somewhat arbitrary and we cheerfully invite helpful criticism.
Proceedings of the Iowa Academy of Science
©1908 Iowa Academy of Science, Inc.
Wheat, G. G. and Wheat, A. J.
"The Life of Portland Cement,"
Proceedings of the Iowa Academy of Science, 15(1), 111-115.
Available at: https://scholarworks.uni.edu/pias/vol15/iss1/19