506 Dr. Schunck on Rubian and its Products of Decomposition 



turbid liquids. The ammoniacal solution gives reddish-brown 

 flocculent precipitates with most earthy and metallic salts. When 

 the solution in caustic soda is boiled, a disengagement of ammo- 

 nia takes place. If erythrozym be treated with boiling nitric 

 acid, it is dissolved and decomposed with a disengagement of 

 nitrous acid. A small quantity of a white flocculent substance 

 remains behind. Concentrated sulphuric acid chars it on 

 heating. 



If erythrozym be mixed with water, and the mixture be allowed 

 to stand for a length of time in a warm place, signs of a more 

 active process of fermentation begin to show themselves, espe- 

 cially in summer weather ; bubbles of gas are given off, and a 

 peculiar smell is emitted, which, though disagreeable, cannot 

 exactly be called putrid. During this process, which is evi- 

 dently one of putrefaction in the stricter sense, the erythrozym 

 loses its sliminess, and is converted into a red flocculent mass, 

 which may easily be separated by filtration from the liquid. The 

 latter is clear, colourless and quite neutral. After erythrozym 

 has passed through this second stage of decomposition, its power 

 of decomposing rubian is found to have lost much of its inten- 

 sity. It is during the first period of its decomposition, when no 

 apparent change is taking place, that this power is most ener- 

 getically exerted. During the second, or more strictly putre- 

 factive stage, it acquires, however, the property of decomposing 

 sugar. If erythrozym be mixed with a solution of cane-sugar, 

 and the mixture be allowed to stand for a considerable time until 

 gas begins to be disengaged, the solution acquires by degrees a 

 decided acid reaction. What the acid is which is thereby formed, 

 I have not yet ascertained. 



The erythrozym which I submitted to analysis, was prepared 

 by precipitating it from an extract of madder with tepid water, 

 by means of alcohol, collecting it on a filter, then treating it re- 

 peatedly with boiling alcohol until all matter soluble therein was 

 removed, and then washing it on a filter with cold water until 

 the percolating liquid no longer gave a precipitate with sugar of 

 lead, after which it was rapidly dried in the water-bath. It 

 follows from the analyses which I have made, that the amount 

 of lime which it contains is tolerably constant, and that it must 

 consequently be considered as a definite compound of an organic 

 substance with lime. 



I. 0-6220 grm., dried at 100° C. and burnt with oxide of 

 copper and chlorate of potash, gave 0*8670 carbonic acid and 

 0-2365 water. 



0*7770 grm. gave 0*4035 chloride of platinum and ammonium, 



0*9630 grm. gave on being incinerated 0*2350 carbonate of 

 hme» 



