908 



SCIENCE 



[N. S. Vol. XLI. No. 1068 



Oligocene, without any information concern- 

 ing their relative ages, he would hesitate to 

 declare which was the older. At the same 

 time, the amber ants do show some relatively 

 primitive features, and Prionomyrmex, from 

 the amber, is absolutely the most primitive of 

 known ants. The nearest living relative of 

 Prionomyrmex is the Australian Myrmecia. 

 It must also be noted that the amber ants have 

 not so far shovpn any marked soldier types, 

 like that of Pheidole. 



Some years ago I had occasion to study the 

 bees of Baltic amber and found all the 

 genera to be extinct, although the fossorial 

 wasps from the same material, so far as seen, 

 were strictly of modern genera. It is cer- 

 tainly true that different genera and families 

 of insects differ greatly in their antiquity, and 

 some of those which we might naturally sup- 

 pose to be relatively recent are in fact very 

 old. Such studies as this of Dr. Wheeler's 

 supply a firm foundation of facts to take the 

 place of guesses, and are of inestimable value 

 to students of evolution. 



t. d. a. cockeeell 



Univeesitt op Coloeado, 

 May 5, 1915 



The Examination of Mydrocarhon Oils and of 

 the Saponifiahle Fats and Waxes. By Dr. 

 D. HoLDE. Translated by Edward Mueller, 

 from the fourth German edition. John 

 Wiley and Son, Inc. 1915. Pp. 483. 

 To present in the limited space of this book 

 even a brief description, and standard methods 

 of examination of the great variety of petro- 

 leum products and fats, demands a compre- 

 hensive knowledge and critical judgment. In 

 the last edition of Dr. Holde's work this object 

 has been well accomplished. 



Petroleum and its products, the most volu- 

 minous part of the subject, occupy the larger 

 space, yet the saponifiable fats and their pro- 

 ducts are quite comprehensively included. 



In its general plan the book presents brief 

 descriptions of properties and composition, 

 general reactions, behavior towards reagents 

 and standard quantitative physical and chem- 

 ical methods of examination. There is a great 

 condensation of subject-matter by means of the 



97 tables that are interspersed throughout the 

 book, and that summarize much valuable data 

 in connection with the subject in hand. 



Products recently brought into commercial 

 use are described with methods of control. The 

 physical examination of the hydrocarbon oils 

 and their derivatives includes specific heat, 

 heat of vaporization, viscosity, calorific power, 

 coefficient of expansion and optical properties. 

 Eotary power of mineral oils receives atten- 

 tion, more especially in European oils where it 

 is apparently more general than in American 

 crude oils, or their products. The recently 

 proposed formolit reaction (formic aldehyde 

 and concentrated sulphuric acid) on mineral 

 oils is described, and some other recently 

 proposed methods. Large space is properly de- 

 voted to lubrication, lubricants and greases, as- 

 phalts and tars. With the marvelous expan- 

 sion in the use of motor power, the several re- 

 cent methods for increased output of gasoline 

 from inferior oils and the general replacement 

 of kerosene for lighting, it appears that gaso- 

 line and lubricants will soon be the principal 

 products refined from petroleum. Much serv- 

 iceable information is presented concerning 

 non-drying oils and solid fats, vegetable semi- 

 drying oils, and drying oils, animal oils and oils 

 from marine sources. The chapter devoted to 

 technical products derived from fats and oils, 

 blown oils, soaps, soap powder, turpentine wood 

 oils, boiled oils, resins and allied products both 

 in description and methods will be found 

 useful. 



Certain looseness in statement appears here 

 and there. Caustic soda is of equal necessity 

 with sulphuric acid in refining to remove sul- 

 phonic acids and particles of sludge that per- 

 meate the oil after the acid treatment. 

 Fuller's earth is used only after acid treatment 

 to remove color. The two general types of 

 petroleum suggested are not inclusive. The 

 writer has a barrel of Russian crude oil that 

 distills to less than one per cent, below 350° 

 at. pres. California, Wyoming, much Kansas, 

 and southern crudes do not fall within this 

 classification. Mercaptans are not contained 

 in American crudes so far as known. On page 

 63 it is mentioned that the method of Oarius 



