Education. 



56 



[July, 1012. 



the latter, whilst barbituric acid gave 

 the greater amount of dry produce. 



The similarity of the two results is 

 probably due to the fact that barbituric 

 acid is readily decomposed with pro- 

 duction of ure and malonic acid. 



The next best result was obtained 

 with acetamide, which gave nearly as 

 much dry produce as barbituric acid, 

 although less nitrogen was assimilated. 

 After acetamide the highest results 

 as regards the amounts of nitrogen 

 assimilated were those obtained with 

 ammonium sulphate (without calcium 

 carbonate), formamide, and alloxam, 

 which assimilated 12*5, 8*5, and 7 mg. of 

 nitrogen respectively, Glycine, alanine, 

 and peptone come next with 5'8, 5-1 and 

 4-8 mg. of nitrogen. Then oxamide (3'6) 

 and guanidine (2*7 mg. nitrogen), and 

 lastly cyanuric acid. 



The assimilation of nitrogen varied 

 from a maximum of 33*7 (culture infested) 

 for urea to a minimum of 1'3 for cyanuric 

 acid + CaCo3. With humates the 

 nitrogen assimilated amounted to only 

 5'9 mg. ; the amount of dry produce was 

 however comparatively high, being more 

 than was obtained with urea. 



The above grouping is only provisional, 

 and it should be remembered that the 

 ability of a plant to utilise the nitrogen 

 of any particular compound depends not 

 only on its power of detaching the 

 nitrogen, but on the nature of the 

 carbon compound or compounds re- 

 maining. A copious bibliography is 

 annexed. 



IS HUMUS A DIRECT SOURCE OP 

 CARBON FOR THE HIGHER GREEN 

 PLANTS ? 



By Marin, Molliard. 



(L'humus est-il une source directe de 

 carbone pour less plantes vertes supe- 

 rieures ?).—Comptes Rendusde VAcadimie 

 des Sciences. Tome 154, No. 5 ; pp. 291- 

 294. Paris 29, Janvier, 1912,) 



(Bulletin of the Bureau of Agricultural 

 Intelligence and of Plant Diseases, 3rd 

 Year— N umber 4, April 1912.) 



After it was established that certain 

 organic substances relatively simple, 

 such as sugar, are absorbed by the 

 higher plants and form food-stuffs for 

 them, the question was asked whether 

 the same was not true for more complex 

 substances and particularly for humus. 

 Besides its theoretical interest, this 

 question is of great practical importance. 



The action of humus on plants through 

 the nitrogenous and mineral substances 

 contained in it has been proved in 

 numerous works but the carbon food of 

 the plant as taken from the soil's humic 

 matter has not yet been demonstrated. 



In a first series of experiments with 

 plants grown in sterilised earth, and pro- 

 tected from the carbonic acid in the air, 

 the writer has shown the effect which 

 humus may produce in plants by reason 

 of its production of carbon dioxide. But 

 the conclusion already reached is that, 

 ■if humic substances are directly assimil- 

 ated by green plants, yet the amount so 

 absorbed is altogether insignificant. 



EDUCATION. 



COURSES IN AGRICULTURAL 

 COLLEGES. 



(From the Journal oj the Board of Agri- 

 culture, Vol. XIX., No. 2 May, 1912.) 

 The Board of Agriculture and Fisheries 



and the Board of Education have recent- 



ly published the fifth report of the 

 Rural Education Conference. The sub- 

 ject of the report is the following re- 

 ference received from the Board of Agri- 

 culture and Fisheries :— 



"To consider and advise as to the con- 

 siderations which should be borne in 



