488 Mr. Mann and Dr. Ince. [Feb. 14— Nov. 5, 



precipitate was formed during that part of the process of clearing the 

 alcoholic percolates from the powdered plant, which was partly effected by 

 blowing air through the liquid to get rid of excess of sulphuretted hydrogen. 

 This precipitate, after repeated recrystallisation from water and alcohol, and 

 treating with decolourising agents, still remained yellow. It is soluble in 

 •alkalies with a deep yellow colour. The silver salt is a faint cream-white 

 precipitate. The free substance contains no nitrogen of sulphur. It is a 

 very weak acid, for the ammonium salt (red-yellow tufts of needles) decom- 

 poses in the air, losing ammonia and reverting to the original acid. The 

 sodium salt is more stable (red-yellow tufts of needles). The acid decomposes 

 without melting on heating. The mean of three analyses, C = 43*5, H = 6*3, 

 H 2 = 10-7. Calculated for C 7 H 10 O 5 H 2 O, C = 437, H = 6'3, H 2 = 9*4. 



The sodium salt gave Na = 19'6. Calculated for C 7 Hio0 6 Na 2 , Na = 19'4. 



Gastroldbin, a vegetable gelatinoid. — In clearing the syrupy percolate from 

 the sulphuric acid extraction, it was noticed that, after the addition of lead 

 ;acetate, the solution became quite limpid. To isolate the mucilaginous 

 principles, the lead precipitate was washed, suspended in water, and decom- 

 posed with sulphuretted hydrogen. The filtrate had regained its viscous 

 character. Absolute alcohol precipitated a flocculent substance, which was 

 soluble in water. The substance does not reduce Fehling's solution and does 

 not contain nitrogen or sulphur. The aqueous solution is precipitated by 

 tannic acid, lead acetate, dilute sulphuric acid, and sodium carbonate. The 

 substance was purified by solution in water and reprecipitation with alcohol 

 (five times). An analysis was made : C = 44*2, H = 6*0 ; CeHioOs requires 

 C = 44 - 4, H = 6 '2. The substance was oxidised with nitric acid, no indica- 

 tions of saccharic, oxalic, or tartaric acids were given, but it yielded the 

 pyrrol test for mucic acid. The substance probably belongs to that ill-defined 

 family of vegetable carbohydrate gelatinoids, of which agar-agar is the best 

 known member. The body is apparently identical with a similar substance 

 described by Professor Stockman in his report. 



Cygnose, C 6 Hi 2 06. — After the removal of the gastrolobin by means of lead 

 acetate, the limpid solution gave tests with phenylhydrazine and Fehling's 

 solution that pointed to the presence of a sugar in the solution. It was 

 found quite impossible to obtain a pure sugar from the solution. The 

 osazone was therefore prepared in the ordinary way. It can be crystallised 

 from alcohol in the form of slender yellow needles, m. p. 179° C. The 

 mean of four analyses gave C = 60*0, H = 6'3, 1ST = 15*7. Calculated for 

 C 6 H 10 O4(N 2 H.C 6 H 5 ) 2 , C = 60-3, H = 61, N = 15-6. 



The sugar itself seems to be optically inactive both before and after 

 inversion. It is not fermented by yeast. 



