35^ Biochemical News, Notes and Comment [Dec. 



soils. Tests made by Professor Hart and Mr. Peterson, however, 

 show that low results were due to the analytical methods employed 

 by the earlier investigators, and according to more accurate deter- 

 minations the sulfur content of our soils is of vast importance. Con- 

 tinuous cultivation, in connection with insufficient fertilization, 

 annually results in a heavy loss of sulfur. Combined with losses 

 of sulfur through drainage and low original sulfur content of the 

 soil, it appears that this loss can not be compensated by the sulfur 

 obtained from the atmosphere. The surface eight inches of the 

 normal soil yield only enough trioxide for about loo normal crops 

 of barley. The fact that the subsoil also has a low sulfur content, 

 shows that the upward movement of capillary water can not bring 

 much sulfur to the surface. In a word, it is necessary to apply fer- 

 tilizers containing sulfur to maintain the crop yields of such soils. 

 These experiments show that the sulfur content of a number of the 

 common farm products, as previously determined, has been too low 

 and that much sulfur trioxide is removed by crops from the soil — 

 more than has been supposed. In fact, soils cropj>ed continuously 

 for half a Century with infrequent applications of fertilizers, have 

 lost as much as 40 per cent. of their original sulfur. 



Book reviews. Immune Sera. A concise exposition of the 

 main facts and theories of infection and immunity. By Charles F. 

 Bolduan, M.D., bacteriologist, research laboratory, Department of 

 Health, City of New York. Fourth edition. London: Chapman 

 and Hall. New York: John Wiley & Sons. 191 1. Pp. xi and 

 226. Price $1.50. 



In the present (its fourth) edition, Bolduan's book is slightly 

 enlarged but fortunately still retains its small and handy size. The 

 book makes no attempt at completeness but is intended as a gen- 

 eral introduction to the complex subject of immunity and is one of 

 the best books for the beginner in this field. From the enormous 

 literature of the past few years the author has managed to summa- 

 rize the most important advances. Some of the matter which he has 

 picked out is open to criticism, but on the whole he has chosen very 

 wisely. The most important of the new subjects are snake venoms 

 and antivenins, anaphylaxis, the Wassermann and Noguchi reactions, 

 the blood examination preparatory to transfusion, the meiostagmin 



