308 H. Stanley Jevons — Nomenclature of Igneous Mocks. 



Table I. List of Contractions for the Names of Minerals. 



The names of structures do not admit of contraction quite so 

 readily as those of minerals, but it is only in very few cases that the 

 name cannot be reduced to three syllables. The list of contractions 

 given below (Table II) is almost complete, but for some words such 

 as hypocrystalline-porpJiyritic and glomeroporpTiyritic, besides granular, 

 granulitic, etc., unambiguous contractions do not exist. It may 

 become necessary, in some cases, to adopt new names for such 

 structures, though I hesitate to go so far at present. Suggestions 

 from any quarter will, however, be gratefully received and con- 

 sidered. In the case of names for which contractions cannot be 

 invented, and which are therefore omitted from the following list, it 

 will probably be best for the present to use the whole name without 

 contraction. 



The contractions are given in the form which should be used 

 when the next syllable begins with a consonant. When followed 

 by a vowel the final -o should in most cases be dropped. The 

 pronunciation remains unaltered in contractions which are formed 

 by the omission of a syllable from the centre of the word. Thus, for 

 instance, the mi- in misphero- is pronounced long as in ' microscope ' 

 or ' microspherulitic,' and not short as in ' miss.' 



The name amygdaloidal is omitted from the list because that 

 structure is merely a secondary derivative of the vesicular structure. 

 As it is generally the rule in naming an igneous rock to imagine it 

 back in its original and unaltered condition, the two structures 



