92 



SCIENCE 



[N. S. Vol. XXXII. No. 811 



the relation of animal experimentation to 

 medicine, hygiene and surgery, and the con- 

 quest of diseases in the animals themselves. 

 Even though one has followed the principal 

 discoveries in medicine as they have been made 

 from time to time, the results when brought 

 together can hardly fail to surprise one whose 

 attention to such subjects has been only casual. 

 Some opulent philanthropist who wishes to 

 do a service to the cause of medical science 

 would do well to authorize the publishers to 

 send copies of this little book to every state 

 senator and assemblyman, and every member 

 of the national congress, so that our law- 

 makers may obtain, without more effort than 

 busy men can well afford, a comprehensive 

 idea of methods of research, upon which they 

 are so often importuned to pass restrictive or 

 prohibitory legislation. 



Mr. Eockefeller has recently endowed a 

 magnificent institution for medical research. 

 Out of it have already come, by methods which 

 the sentimental zoophilists have so severely 

 condemned, discoveries whose value to the 

 world are many times greater than the cost of 

 the institution. If the well-meaning oppo- 

 nents of animal experimentation had had their 

 way these discoveries would not have been 

 possible. The country would have saved sev- 

 eral of its guinea-pigs and homeless dogs, but 

 it would have lost more of its children. 



We are never entirely safe from the good 

 intentions of the opponents of vivisection, and 

 it is hoped that Dr. Warbasse's book will be 

 widely circulated and will serve as a corrective 

 of the misinformation which has been so lib- 

 erally furnished to the public. 



S. J. Holmes 



SCIENTIFIC JOURNALS AND ARTICLES 

 The contents of the current number of the 

 American Journal of Mathematics is as fol- 

 lows : " The Osculants of Plane Kational 

 Quartic Curves," by H. I. Thomson; "On the 

 Primitive Groups of Classes Six and Eight," 

 by W. A. Manning; " Minimalcurven als 

 Orter von Kriimmungsmittelpunlcten," Von 

 E. Study; "Minimalcurven und Serret'sche 

 Elachen," Von E. Study; "On Steinerians of 



Quartic Surfaces," by John N. Van der Vries; 

 " On the Determination of the Ternary Mod- 

 ular Groups," by E. L. Burger; "Groups of 

 Transformations of Sylow Subgroups," by G 

 A. Miller. 



. SPECIAL ARTICLES 



ON THE GENERAL USE OF THE GRATING ^VITH THE 

 INTERFEROMETER 



In a recent number of this journal' a 

 method was described of bringing reflected- 

 diffracted and diffracted-reflected rays to in- 

 terference, producing a series of phenomena 

 which in addition to their great beauty prom- 

 ise to be useful. In fact, the interferometer 

 so constructed needs but ordinary plate glass 

 and replica gratings. It gives fringes rigor- 

 ously straight, and their distance apart and 

 inclination are thus measurable by ocular 

 micrometry. An adjustment may be made 

 whereby ten small fringes occupy the same 

 space in the field as one large fringe, so that 

 sudden expansions within the limits of the 

 large fringe (as in magneto-striction) are 

 determinable. Lengths and small angles are 

 thus subject to micrometric measurement. 

 Finally the interferences are very easily pro- 

 duced and strong with white light, while the 

 spectrum line used may be kept in the field 



^ ^ 



'From a lecture given to the Eastern Associa- 

 tion of Physics Teachers, at Brown University, 

 Providence, on May 21, 1910. See also C. and M. 

 Barus, ScmxcE, JIarch 11, 1910. p. 394, and a 

 forthcoming number of the Philosophical Maga- 

 zine. 



