Januaky 8, 1904.] 



SCIENCE. 



69 



products of a -pyi'olydin-carbonic acid could 

 not be established with certainty. 



A Besiant Source of Error in Optical Sugar 



Analysis: F. G. Wiechmann. 



Dr. Wiechmann's paper dealt with the error 

 due to the space occupied by the precipitate 

 formed by basic lead acetate used as a clari- 

 fying agent. After a discussion of the extent 

 of the error thus introduced in the examina- 

 tion of different classes of raw sugars, the 

 author outlined briefly the results of a study 

 of the methods proposed by Scheibler and by 

 Sachs for the determination of the volume of 

 the precipitate. This paper will be found in 

 the School of Mines Quarterly for November, 

 1903. 

 Dry Defecation in Optical Sugar Analysis: 



W. D. HORNE. 



Dr. Home described a method for clarifying 

 sugar solutions so as to avoid or minimize the 

 error discussed by Dr. Wiechmann. The 

 ' normal weight ' of sugar is dissolved and 

 diluted to 100 cubic centimeters and the solu- 

 tion clarified by the addition of pulverized 

 anhydrous subacetate of lead. The acetic acid 

 going into solution appears to replace in vol- 

 ume the organic acid, precipitated by the lead, 

 so closely that the polarizations obtained on 

 such solutions approximate the theoretical. 



After the reading of the above papers, Dr. 

 G. Plath, of Berlin, exhibited and explained 

 a number of specimens of improved stoneware 

 apparatus designed for use in chemical opera- 

 tions. 



H. 0. Sherman, 

 Secretary. 



chemical society of WASHINGTON. 



The 146th regular meeting of the Wash- 

 ington Chemical Society was held Thursday, 

 December 10, at 8 p.m., in the assembly room 

 of the Cosmos Club. The program for the 

 evening consisted of the following three papers. 



The first paper, entitled ' The Bromine Ab- 

 sorption of Oils,' was presented by Mr. L. M. 

 Tolman. 



A comparison of the results obtained by dif- 

 ferent methods was made, and it was shown 

 that the one third normal bromine in carbon 



tetrachloride gave as high addition figures as 

 the Wij's and Hanus methods, when the car- 

 bon tetrachloride was dry and the reaction 

 was allowed to take place in the light. Moist- 

 ure was found to have a very marked effect on 

 both the addition and substitution values. 

 The length of time necessary to obtain com- 

 plete reaction was found to vary in the light, 

 30 to 60 minutes being necessary, while in the 

 dark a definite point was reached in a very 

 short time, but the results were much below 

 those obtained in the light. Experiments were 

 reported using iodine chloride and iodine 

 bromide in carbon tetrachloride solution. The 

 iodine chloride in carbon tetrachloride was 

 found to be the most satisfactory. 



The second paper on the program, entitled 

 ' The Action of Sal Ammoniac on Certain 

 Chlorides,' was presented by Dr. P. Fireman. 

 The action of ammonium chloride upon inor- 

 ganic and organic polychlorides in sealed tubes 

 at temperatures about 450° C. was investi- 

 gated. The author found that those inorganic 

 polychlorides which are themselves dissociable, 

 react with ammonium chloride in a manner 

 similar to the reaction between ammonium 

 chloride and phosphorus pentachloride. With 

 respect to organic polychlorides, it was found 

 that under certain conditions carbon tetra- 

 chloride reacts with ammonium chloride, with 

 the liberation of hydrochloric acid and the 

 formation of a yellowish compound which is 

 probably a polymeric modification of cyanogen 

 chloride. 



The third paper on the program, entitled 

 'The Solubility of some Slightly Soluble 

 Phosphates,' was presented by Dr. F. K. Cam- 

 eron. The author briefiy reviewed the litera- 

 ture bearing on the solubility of the phos- 

 phates of calcium, aluminum and iron, and 

 gave a preliminary announcement of some 

 experimental investigations he has been car- 

 rying on with Dr. Seidell and Mr. Hurst. It 

 appears that the evidence obtained can not 

 be brought in harmony with the indications of 

 the dissociation hypothesis, even in very dilute 

 solutions. But some of the apparent discrep- 

 ancies between the hypothesis and the ob- 

 served facts are undoubtedly due to the fact 



