Society of Public Analysts 205 



tion is hastened by pressure applied to the bottle by means of a tube 

 passed through a bung, which also carries the pipette. In this way 

 20 cc. of clear sol. is removed. The fat in it is determined after 

 evaporation of the solvent. The total weight of fat in the substance 

 taken is determined by multiplying by a factor, which varies accord- 

 ing to the weight of fat obtained. Thus, if 0.3 gm. is obtained, the 

 factor is 5.04; if 0.5 gm., 5.11 ; if 0.7 gm., 5.165. 



A new colour reaction f or aloes. C. E. Stacy. A pink colour- 

 ation sufficiently delicate to detect one part of Barbadoes aloes in 

 10,000 is produced by the addition of a freshly-prepared sol. of 

 potassium ferricyanide to the cold aqueous sol. of the aloes, under 

 the conditions named. By the difTerence in colour of the reaction the 

 author claims to be able to distinguish certain different varieties of 

 aloes used in medicine, from each other and from commercial aloin 

 in med. preparations. 



II. Ordinary Meeting, ßth April, 1916. Held at the Chem. Soc. 

 Rooms, Burlington House, London. Mr. George Embrey, Presi- 

 dent, in the Chair. 



Mr. Frank Theodore Alpe was elected a member of the society. 

 A certificate was read for the second time in favour of Mr. Maurice 

 S. Salamon. 



The papers abstracted below were read and discussed : 



On the alkalimetric estimation of certain bivalent metals in 

 the form of tertiary phosphates, with especial reference to the 

 Volumetrie determination of cobalt and nickel. W. R. Schoeller, 

 Ph.D. and A. R. Powell. Stolba's alkalimetric method for the esti- 

 mation of phosphoric acid in magnesium ammonium phosphate is 

 also used for the determination of magnesium, and has been ex- 

 tended to that of zinc in zinc ammonium phosphate. The authors 

 have demonstrated the applicability of the process to cadmium, man- 

 ganese, and cobalt. On dissolving cobalt ammonium phosphate in a 

 measured volume of m/5 acid and titrating back the excess of the 

 latter, the intense colour of the sol. rendered most indicators useless. 

 Results obtained with cochineal were always 0.5-2 mg. high, due 

 to the action of cobalt on the indicator. By suspending cobalt am- 

 monium phosphate in water and adding n/5 acid until the precipi- 

 tate just disappeared, satisfactory results were obtained. It is shown 



