584 



SCIENCE 



[N. S. Vol. XXXIII. No. 850 



but the material was so abundant that the 

 issue of a third, and finally of a fdurth vol- 

 ume became requisite. 



In his preface to the first volume M. Lacrois 

 calls attention to the fact that France has 

 been commonly regarded as a land poor in 

 minerals, and he finds an explanation of this 

 belief in the comparatively slight favor that 

 has been accorded to mineralogical studies 

 there. A careful consideration of the geolog- 

 ical features of that land, the great develop- 

 ment attained there by the crystalline schists, 

 by the ancient eruptive rocks, and by the later 

 volcanic ones, should have served as proof 

 that a great variety of mineral forms would 

 be found. The author has sought in every 

 case to trace the mineral to its original 

 source and, as far as possible, to study the 

 conditions controlling its production. 



While it is essentially a treatise of descrip- 

 tive mineralogy that M. Lacroix has produced, 

 he has sought to give, in the case of each 

 mineral, all the information necessary for the 

 student regarding composition, optical prop- 

 erties and general characteristics, so that 

 there might be no necessity to have recourse 

 to other manuals. The crystallographic data 

 are given both in the notation of Levy-Des 

 Cloizeaux and in that of Miller, and this 

 greatly facilitates the use of the book for 

 those unfamiliar with the French notation. 

 The measurements given are all from speci- 

 mens secured in the French deposits, the 

 greater part of which have been collected by 

 the author himself. 



The considerable interval of time inter- 

 vening between the issue of the second, third 

 and fourth volumes, and the accumulation of 

 new data — especially from Madagascar — that 

 the author has collected during the past de- 

 cade, renders the last volume a supplementary 

 one; but the various new items are always 

 referred to their proper place in the general 

 scheme of the work. 



The rich material has been arranged, in the 

 main, according to the classification of Groth, 

 and the full and accurate index renders it an 

 easy matter to find the information given in 

 regard to each mineral. The small percentage 



of mineral substances not included in the 

 work are those which have not been found in 

 France or in her colonies. The number of 

 gem-stones — that is, of stones furnishing gem- 

 material — is comparatively small, except in 

 the case of the Madagascar deposits. Of the 

 precious metals also there is no great abun- 

 dance, in spite of the well-known fact that in 

 Roman times the Gauls were exceptionally 

 well supplied with gold. They appear to have 

 nearly exhausted the deposits with which they 

 were acquainted, and no new ones of equal 

 value have since been discovered. In this 

 connection, we may note (Vol. II., p. 422) an 

 illustration figuring a gold medal struck in 

 1'786, and made from the first ingot secured 

 from the mine of La Gardette, dept. Isere. 



The fourth volume is largely occupied with 

 the treatment of the great variety of minerals 

 found in the French colony of Madagascar, 

 many of these having been collected by M. 

 Lacroix in 1902 and 1903, when he was on an 

 oificial mission to the island. More especially 

 the pegmatite rocks of Mt. Bity and its neigh- 

 borhood have yielded fine specimens of a great 

 many types and varieties with which we are 

 already familiar, and also some that are new 

 or have not been met with in the same perfec- 

 tion elsewhere. Among these may be noted a 

 new species, bityite, named by M. Lacroix, and 

 the beautiful pink variety of beryl, which the 

 writer of the present review has named mor- 

 ganite, in honor of our distinguished fellow- 

 citizen, J. Pierpont Morgan. As the begin- 

 ning of the systematic search for minerals in 

 Madagascar is of such recent date, we may 

 hope that the future has other pleasant sur- 

 prises in store for us. 



In the course of the publication of this 

 work, begun eighteen years ago, the author 

 was elected a member of the Academie des 

 Sciences in Paris, an honor no one has better 

 deserved than he. His single-hearted devotion 

 to the progress of science is well shovsai in the 

 following words prefixed to the last volume of 

 his book : " I shall consider myself amply re- 

 warded for my long task if this book should 

 help to stimulate the study of the natural his- 

 tory of minerals in France." 



