CONVENTION OF OFFICIAL AGRICULTURAL CHEMISTS. 413 



found that there was no necessity for ehronihio- hide longHM- than 

 1 day. He uryed, therefore, that the chroming- of hide powder 24 

 hours with 8 gin. of clironie ahun per loo gni. of hide powder be made 

 the oflScial method, and also ad\'ocated a provisional method for dry 

 chromed hide, to be carefully experimented with during" the coming 

 year. In making- up the solution of tanning materials it was recom- 

 mended that an amount be taken sufficient to furnish 0.35-0.45 gm. of 

 tannin per 100 cc. instead of 0.8 gm. of solids, as at present. In evap- 

 orations 50 cc. was considered too small, and 100 cc. was therefore 

 advocated for obtaining all residues. A number of modihcations were 

 recommended in the official method. 



A report of the meeting- of the International Association of Leather 

 Trades Chemists, which met at Liege, Belgium, on August 28, was 

 made b}- W. H. Krug. The changes in the methods used b}' that 

 Association were (1) the adoption of Freiberg- hide powder, the maxi- 

 mum cellulose content to be 20 per cent and the manufacturer to mark 

 each delivery with the percentage it contains; (2) the adoption of the 

 Official Agricultural Chemists' method for used tanyard liquors. The 

 chromed hide powder method was not very favorably considered bj^ 

 the International Association. In conclusion the speaker read a letter 

 from H. li. Proctor on the correction for the absorption of the filter 

 paper in the determination of the soluble solids, and suggested that it 

 be made the subject of an investigation by the referee for the ensuing 

 year. 



Minor changes were made in the wording of the methods to cover 

 the recommendations of the referee. The wet chromed hide powder 

 method was adopted in lieu of the one now followed, and the drj'- 

 chromed hide powder method was adopted as an optional one. The 

 determination of the acidity of tan liquors was recommended for study 

 during the ensuing year. 



INSECTICIDES AND FUNGICIDES. 



The report on the majority of these materials was made b}^ the ref- 

 eree, L. A. Voorhees. The past year was the first year in which anj'^ 

 anah'tical work of a cooperative nature has been undertaken on these 

 materials. The results obtained b}^ 22 anah'sts were reported in 

 detail. As the}^ were somewhat meager, the referee did not make an}'^ 

 specific reconmiendations, but called the attention of the association to 

 the following considerations: (1) That the detection and determination 

 of formaldehyde does not properly l)elong to the referee on agricultural 

 insecticides and fungicides; (2) that the content of cyanogen in cj'anid 

 of potash is of interest, but for fumigating the determination of impuri- 

 ties and the character of gases which they supply will be of more value; 

 (3) that the purity of lyes for the home making of insecticide soap is of 

 importance, but as to the soaps themselves there is much in their 



