696 



SCIENCE 



[Vol. LVI, No. 14-59 



Gladding method as official by the Association of 

 Official Agricultural Chemists, with modifications 

 which have been made since. The official method, 

 although popular with analysts, gives low results 

 and suggestions are made as to modifications, 

 which may be used to recover all the available 

 potash. It is recommended that the fertilizer 

 division take up the matter and work out aa accu- 

 rate method, which will be acceptable to the As- 

 sociation of Official Agricultural Chemists. 



Some sources of error in the determination of 

 insohible phospJiorio acid in acid phosphate and 

 fertilisers: "W. B. ArsTiN. 



Some sources of error in the determination of 

 total phosphoric acid in acid phosphate and fer- 

 tilizers: W. E. Austin. 



A qualitative scheme for the detection of cyan- 

 amide and related compounds: G. H. BrcHANAN. 

 Quantitative methods for the determination of 

 cyauamide and its transformation products are 

 only of value when preceded by a reliable qualita- 

 tive examination. A qualitative scheme is pre- 

 sented, modeled after the ordinary schemes of 

 inorganic analysis, whereby ten forms of nitrogen 

 which are commercially related to cyanamide may 

 be detected. Provision is made for the inter- 

 ference of the more common inorganic radicles. 

 The ten forms included in the scheme are as fol- 

 lows: (1) Ammonia and its salts; (2) Cyana- 

 mide; (3) Hydrocj'anic acid and its salts; (4) 

 Dicyandiamide ; (5) Guanidine and its salts; (6) 

 Quanylurea and its salts; (7) Nitric acid and its 

 salts; (8) Thiocyauic acid and its salts; (9) 

 Thiourea; (10) Urea. Comments relating to the 

 behavior of several other less common nitrogenous 

 forms are also made. 



The importance of correct methods of applying 

 fertiliser: E. J. Pranke. Faulty methods of 

 applying fertilizer in the seed row in direct con- 

 tact with the seed frequently causes visible dam- 

 age to the crops, for which the grower often seeks 

 to recover compensation from the fertilizer manu- 

 facturers. There is probably also a great deal of 

 invisible damage caused by improper method of 

 applying fertilizer. The effect of the relative 

 position of seed and fertilizer on the efficiency 

 of the latter, as developed in extensive researches 

 conducted during the past three or four years, is 

 discussed. 



Fertilization in relation to plant composition: 

 H. A. Notes. Mention was made of different 

 methods of testing the fertilizer requirements of 

 soils. A study of these methods showed that the 

 users of fertilizers measure results, almost eu- 

 tirelj', on the increases in the marketable portions 



of the crop grown. There are many reports of 

 increased crops resulting from fertilization but 

 very little information of the character and com- 

 position of the plants. Industries which manu- 

 facture food-stuffs from grains and fruits find 

 the control of their finislied products difficult, due 

 to immense variations in the composition of the 

 grains and fruits which serve as their raw ma- 

 terials. Data was presented showing that large 

 variations exist in the composition of two eco- 

 nomic plants. A plea was made for a study of 

 the optimum analyses for each economic agricul- 

 tural crop. Such a study would cause fertilizer 

 results to be judged in terms of variations toward 

 or away from the optimum analyses. As a result 

 of a long series of investigations of one crop 

 under field conditions the following hypothesis 

 was evolved. When the optimum composition for 

 any two parts of a plant is worked out it will he 

 possible to determine how to fertilise the soil by 

 studying the ratio that exists between the analysis 

 of the different portions of the plant. 



Replacement of plant food adsorbed by the 

 hydrogels of ferric oxide and alumina: A. L. 

 Plenner, a. L. Lichtenwalner and N. E. 

 GoEDOiJ. The hydrogels of ferric oxide and 

 alumina were allowed to suffer their maximum ad- 

 sorption of salts. Wlen this equilibrium had been 

 reached the gels were subjected to successive 

 washings with distilled water, and when 50 co. of 

 the filtrate failed to give more than a very slight 

 test for the adsorbed salt, the gel was subjected 

 to washings with various acid, base and salt solu- 

 tions, and the resulting filtrates analyzed for the 

 respective salts. Analj-sis of the gel was made at 

 each change of the leaching solution. 



Can plants use salts adsorbed by soil colloids: 

 E. C. Wiley and N. E. GoRDOisr. Experimental 

 work was started in order to find if plants were 

 able to use salts which had been adsorbed by soil 

 colloids. The soil colloids were artificially pre- 

 pared, and after they had suffered a maximum 

 adsorption of the various salts used in plant 

 nutrition work, the plants were allowed to root 

 and grow in the colloids. After a certain period 

 of growth the plants were analyzed for the quan- 

 tity of different elements which the plants had 

 been able to take up from the colloids. 



Utilisation of waste products for organic nitro- 

 gen: E. H. Armstrong. The comparative abun- 

 dance of materials carrying organic nitrogen in 

 available form which were to be had in the early 

 stages of the fertilizer industry; the gradual 

 withdrawal of these from the fertilizer materials 

 market to the feed market; the use of part mia- 



