AGRICULTURAL CHEMISTRY — AGROTECHNY. 715 



A blank of distilled water is then titrated in the same way, and tlie true 

 volume of acid required for the back-titration of the sodium acetate obtained by 

 difference. Solutions containing known amounts of acetic acid, sodium acetate, 

 and sulphuric acid were analyzed by this method. 



Analysis of paprika, A. de Sigmond and M. Vuk {KisMet. Kozlem., 1^ 

 (1911), No. 5, pp. 757-792). — The determination of the iodin number and the 

 refraction of the ether extract will not detect adulterations of paprika with 

 foreign oils. The standards of the United States require that paprika represent 

 only the dried fruit of Capsicum annuum, while in Hungary the seeds are not 

 excluded. As the seeds contain more oil, the United States standard of 15 per 

 cent is exceeded. 



Air-dried paprika contains more or less moisture, so that the results obtained 

 should be compared on a dry basis. The results obtained by drying in a current 

 of air differ markedly from those after drying in a current of illuminating gas. 

 It is stated that Hungarian paprika can not be distinguished from foreign 

 paprikas on the basis of a chemical examination. 



Contribution to the detection of benzoic acid in foods and condiments, E. 

 PoLENSKE (Arb. K. Gsndhtsamt., 38 (1911), No. 2, pp. lJ,9-15f,) .—The author 

 has elaborated a method for determining the total benzoic acid in red bilberries 

 and in bilberry compote, and presents a method for the isolation and qualitative 

 detection of benzoic acid in food products. 



Determination of the total solids in milk, A. Splittgerber (Ztschr. TJnter- 

 such. Nahr. u. Genussmtl., 22 (1911), No. 10, pp. 583-599; abs. in CJiem. Zentbl., 

 1912, I, No. 5, pp. 377, 378; Jour. Soc. Chem. Indus., 31 (1912), No. 1, pp. 40, 

 41). — What is deemed the most appropriate method for determining the 'total 

 solids in milk consists in drying from 3 to 4 gm. of milk in a flat-bottomed dish 

 with or without the addition of acetone or alcohol. The method yields results 

 with normal, rich, skim, and watered milk, which compare well with the figures 

 obtained by Fleischmann's formula. The ordinary water oven requires 1 hour 

 for the process, while the Soxhlet oven needs only 30 minutes when a watery 

 solution of glycerin (55 per cent) is used. The addition of 3 drops of acetic acid 

 or formaldehyde to the milk before evaporation yields results which are too 

 high. Old milks yield low results. " If the milk contains calcium sucrate or 

 sodium carbonate, the quantity of total solids found by direct determination is 

 unreliable, but in such cases the calculated figure may be relied on as trust- 

 worthy." 



The chlorin content of milk, P. Poetschke (Jour. Indus, and Engin. Chcm., 

 4 (1912), No. 1, pp. 38-40). — The chlorin determinations recorded were made 

 by the author's method, which consists in removal of the fat and proteids with 

 copper sulphate and sodium hydroxid. The filtrate is acidified with nitric acid 

 and titrated by Volhard's method. Total solids were determined with the aid 

 of a special pipette (E. S. R., 26, p. 806) devised to deliver 5 gm. of milk. 



The average amount of chlorin found, expressed as sodium chlorid, was 0.17 

 per cent, and ranged from 0.112 to 0.335 per cent. The average ratio of sodium 

 chlorid to ash was 1 : 4.5. 



Titrating the milk directly for its chlorin content, as recommended by 

 Richmond, gave erroneous results. Foi-maldehyde present to the extent of 

 1 : 500 in milk did not influence the results obtained with the author's method. 



A rapid means for determining the fat in milk according to the Eose- 

 Gottlieb method, E. Rupp and A. MtiLLER (Ztschr. Untersuch. Nahr. u. Oe- 

 nussmtl., 23 (1912), No. 7, pp. 338, 339).— The author found that the separation 

 of the ether can be accelerated by adding gum tragacanth to the mixture and 

 shaking. 



