464 EXPERIMENT STATION RECORD. 



The results were not very uuiforin, but the reporter recommeuded the 

 following, which was adopted: lu the exaniinatiou of feeding- stuffs by 

 the Kjeldahl method sulphuric acid containing phosphoric acid is to 

 be used, together with the addition of a sufficient amount of mercury. 

 Digestion for more than 3 hours is unnecessary. 



The proposed imperial control of the trade in feeding stuffs, fertil- 

 izers, and seeds was considered by the association. While the need of 

 such control was conceded, attention was called to the fact that the 

 l^osition which the experiment stations have long occupied with respect 

 to this work was not properly recognized in the proposed statute. 



A report of comparative determinations of potash in a normal sample 

 of kainit^ at 31 laboratories was submitted by M. Maercker. 



The difference between individual determinations is not so large as 

 in previous years, the variation being from 12.72 to 13.61 per cent. 



The long and short methods of Fresenius were compared and the 

 following conclusions were reached : 



(1) With the short method the use of 80 per cent alcohol appears to 

 be indispensable, since stronger alcohol gives higher results. 



(2) In many instances it was observed that the barium chlorid 

 contained potash, and therefore a blank analysis is advisable. 



(3) Hydrochloric acid solutions appeared to give higher results than 

 water solutions. Further tests of this subject were advised. 



(4) In the short method it is necessary to dissolve the precipitate in 

 hot water and weigh the residue, since the potassio-platinic chlorid 

 usually contains considerable amounts of imi)urities. For this pur- 

 pose a Gooch crucible is especially convenient. 



In order to get accurate results it is stated that only a very slight 

 excess of barium chlorid should be used and the solution evaporated 

 with iilatinum chlorid only to a sirupy consistency. 



The section on fertilizers was instructed to study the question of the 

 water solubility of potash in fertilizers in cooperation with the Kali 

 Syndicate, and those members of the association, Halenke and Wag- 

 ner, who have the greatest interest in the Albert salts were requested 

 to investigate the nature of the jjotash and phosphoric-acid compounds 

 in these preparations and to make vegetation experiments regarding 

 their fertilizing value. In determining the soluble potash it is directed 

 that 10 gm. of material which has passed a 1 mm. sieve shall be boiled 

 for 15 minutes with 400 cc. of water. After cooling the solution is to 

 be made to 500 cc. and an aliquot part used for the determination. 



G. Loges submitted a report on the determination of ammoniacal 

 nitrogen in ammoniated superphosphates. This is devoted principally 

 to meeting the objections raised against the determination of ammonia 

 by distillation with magnesium oxid. He shows first that the use of 

 magnesium oxid gives as high results on both 1 gm. and one-half gm. 



'The discordant results reported at the previous raeoting were attributed to the 

 fact that an abnormal sample of potash salt was used for the tests. 



