Go to National Library of New Zealand Te Puna Mātauranga o Aotearoa
Volume 3, 1870
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Diorite.

  • Dana:—Felspar and hornblende Triclinic.

  • Cotta:—Felspar and hornblende Triclinic.

From the above it will be at once apparent that the German classification is not practical, i. e., it cannot be used in the field, for it is rather too much to expect that a geologist, with only an acid bottle, pocket lens, and knife, can decide with any degree of certainty on the angles a half-embedded crystal makes, or the system it belongs to; for although orthoclase is monoclinic and oligoclase triclinic, still the angles are very nearly the same, (albite) 118°a or 120°o 86°a or 90°o etc., etc. The inconvenience of this classification is well shown by the fact that Werner, who first proposed it to suit a certain rock, subsequently called the same rock a diorite. If, however, the English system is adopted, there can be no hesitation in at once determining the quartz, felspar, and hornblende; felspar and hornblende come in as hornblende rock if the felspar is decidedly triclinic, if not, as a diorite.

The English school, or rather the American branch of it, has many claims to preference over all others, chiefly on account of its simplicity, and this simplicity is insured for some time to come, as the Americans have so much room for real practical science, and cannot afford to waste time and talents in multiplying names and then finding out some compound to suit them; the old proverb about a certain personage finding mischief for idle hands, applies to the natural sciences as well as anything else, for when a certain point has been

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reached, many men seem to get tired of good healthy work, and instead of exploring fresh fields go over the old, and keep magnifying minor differences into groups of families, to the complete confusion of everything; forgetting that the great aim of all science is simplicity, and the more simple a science the grander and nobler it is.