158 Scientific Intelligence. 



Percentage of water. 



At surface 1*30 



" 0.20 6-03 



" 0-40 7-87 



" 0-60 11.42 



" 0'80 12-45 



" 1*00 subsoil. 14-24 



These tables are interpreted by M. Reiset as showing that 

 while lawn-grass is wholly scorched in soil having 6-80 to 7*84 

 per cent of water, wheat can grow and ripen when there is 

 only 1-22. r gfefe very vulnerable point in this conclusion is par- 

 tially recognized by M. Reiset, who admits that at the time when 

 his observations were made, the wheat was approaching or had 

 reached maturity. Our readers can see that at that moment the 

 wheat plant could jet on fairly well with far less water than 

 could the lawn-grass in the park. g. l. g. 



8. Nitrification. — M. Deherain (Comptes rendus, May 15, 

 1893) has recently reviewed this important subject, endeavoring* 

 to gain some hints as to the possibility of increasing the nitrifica- 

 tive activity of the soil in the spring. He was surprised at the 

 prodigious amount of available nitrogen in soil received by him 

 from diverse sources, and where there had probably been no 

 addition of sodium nitrate as a manure. He at once began 

 experiments on the effects of violent agitation on different soil, 

 acting on a suggestion of Schloesing that trituration and shaking 

 by distributing the "ferments" might increase the energy. The 

 soils on which he experimented were placed under different con- 

 ditions : one sample of each being kept perfectly at rest; a second, 

 exactly like the first, was from time to time for about six weeks 

 stirred up very thoroughly and like the other exposed to the 

 open air. 



Sample 1. Sample 2. Sample 3. 



Kept still. Shaken. Kept still. Shaken. Kept still. Shaken. 



(1) 2 44 2 51 2 71 



(2) 3 39 2 46 2 57 



These figures are of milligrams of available nitrogen in 100 

 grams of soil. ' 



Further interesting observations show that the ferme its are 

 not equally active at all times even in the same season, and fur- 

 ther that the artificial increase in nitrificative activity at the 

 beginning of winter when the useful products may be so easily 

 lost is absolutely prejudicial. 



Better appliances than those in use would appear to be de- 

 manded by the highest type of effective agriculture, and to this 

 should be added also the selection of the most favorable time for 

 stimulating such activity, namely just when the young plants are 

 ready to utilize the products. g. l. g. 



9. The action of the Pyocyanic bacillus on plants. — M. 

 Charrin (Comptes rendus, May 8, 1893) presents an account of 



