24 EXPERIMENT STATION RECORD. 



follows: Precipitate iu dilate solution with a mixture of magnesium 

 chlorid, ammonium chlori'% and ammonium acetate, in the presence of 

 a decided excess of acetic acid, keeping- the whole for 3 or 4 hours in a 

 boiling water bath. By Ihis method practically the whole of the pyro- 

 phosphoric acid is precipitated, but the orthophosphoric acid, if present, 

 remains in solution. The precipitate is washed, dissolved in nitric acid, 

 and the phosphoric acid determined by precipitation with magnesia 

 mixture in the usufl way. 



It was found that the precipitate obtained by this method from solu- 

 tions of metaphosphoric acid were almost identical with that obtained 

 from a solution 'i" pure sodium pyrophosphate. The chemical char- 

 acter of the precipitate is discussed and investigations on the chemis- 

 try of the transformation of the different forms of phosphoric acid, 

 especially pyrophosphoric acid and metaphosphoric acid, are reported. 



The determination of potash, A. Mercier (BhI. Assoc. Beige, 10 

 {1897), pp. 103-405; abs. in Analyst, 22 {1897), tfo.254,p. 138).— The 

 principal feature of this method is the substitution of mercurous chlo- 

 rid for sodium formate in the reduction of the potassium-platinum 

 chlorid. The method is as follows : I Hgest 5 or 10 gm. of the substance 

 (according to its content «>f potash) for 1 hour in .~»00 cc. of cold water, 

 and filter; evaporate 25 or 50 cc. of the filtrate to dryness on a water 

 bath after the addition of 1 cc. of hydrochloric acid. Expel ammonium 

 compounds from the residue by gentle ignition, take up in very dilute 

 hydrochloric; acid, and filter if necessary. Add 10 cc. of 10 per cent 

 platinic cholorid solution, evaporate to a sirupy consistency on a 

 water bath, cool, and extract with a mixture of 50 cc. of 80 per cent 

 alcohol and 5 cc. of ether. Wash well on the filter with the alcohol 

 ether and dissolve in boiling water. Bring the solution thus obtained 

 to the boiling point, add mercurous chlorid little by little until a 

 deposit forms on the bottom of the beaker (2 gm. are usually suffi- 

 cient). Boil five minutes, allow the platinum to settle, then add 1 to 2 

 cc. of hydrochloric acid, and boil again. Filter; when cold wash the 

 platinum thoroughly with boiling water, and ignite. The potash is 

 estimated by multiplying the weight of platinum obtained by 0.4835. 

 Besults closely agreeing with the theoretical amounts were obtained by 

 this method. 



The carbohydrates of the tubers of Cyclamen europaeum, B. I.'aymax | Roz- 

 pravy cesM akademie, 1896, II. No. SO; «l>s. in Chem. Centr. Bl., 1897, 1, No. 4, p. 280).— 

 Seventy per cent alcohol extracts cyclamose and cyclamin. Cyclamin is a glucosid 

 and yields on hydrolysis cyclamiretin, CY,H,.< > . fructose, and a dextrorotatory sugar 

 which the author lias called cyclose. Cyclamose is an amorphous white powder, 

 Brightly sweet and deliquescent. With HCl it gives levulose; the composition is 



(' .11, » I .■,.— W. 11. KRUG. 



On the action of alkali solution on the phenylosazones of di- and polysac- 

 charids, C. J. Lintneb {Chem. Ztg., 20 {1896), p. 768).— When hot saturated aque- 

 ous solutions of the osazones of maltose, galactose, and melibiose are boiled with 

 alkali solution glyoxalosazone is formed and separates in small docks. The same 



