The phlorogliicol reaction ^with a pine shaN'ing and hydrochloric acid), 

 was obtained with the extract of all the CaUitris barks, although with some of them 

 it was but slight. 



This reaction with C ghiitca was less pronounced than with either 

 C. calcaratu or C. arenosa ; and all the barks belonging to the group of which 

 C. glauca is the type, did not give the reaction at all strongly. It was not given 

 with the filtrates after treating with hide powder, except when these were con- 

 siderably concentrated, so that the constituent to which this reaction is due was 

 largelv removed by that substance. 



The colour reaction with stannous chloride and hydrochloric acid was 

 marked with most samples of C. calcarata, although C. arenosa hardly showed 

 any reddening. The remaining barks all gave a red colour more or less distinctly, 

 but the test has little distinguishing value. 



To arrive at the value or otherwise of the outer cortex of the barks of 

 C. calcarata and C. arenosa, as well as that of the softer external portion of 

 C. glauca, it was decided to submit the bark of the same tree, from these three 

 species, to a double determination. In one case the whole bark was taken, and 

 then a portion was " rossed," the outer layer being removed until a smooth 

 surface was obtained. In this way the barks were reduced to about half their 

 thickness. With C. calcarata, the bark, taken from a tree 3 to 4 inches in diameter, 

 gave with the whole bark 30-93 per cent, of tannin, while the " rossed " bark gave 

 36-1 per cent., showing that a lesser amount of tannin was contained in the outer 

 corky layer. There was not much difference, however, in the colour of the hide 

 powder obtained from either extract. 



With C. arenosa the thick whole bark gave 25-1 per cent, tannin, and the 

 inner " rossed " bark 34.77 per cent. The same " rossed " bark extracted 

 entirely by cold water, during eighteen hours, gave 28-5 per cent, of tannin. It is 

 thus evident that the outer cortex contains con.siderably less tannin than the inner 

 portion. In section, there was but little difference in the appearance of the 

 inner and outer cortex of C. calcarata and C. arenosa, although the latter seems 

 to be distinguished in the freshly stripped green bark, by a more marked crimson 

 band next to the corky layer ; this, however, becomes lost on drying, and it does 

 not seem to have any darkening effect on the extract. 



With C. glauca the whole bark gave 10-5 jxr cent tannin, and the inner 

 "rossed" bark 12-8 per cent, so that it would be hardly worth the trouble to 

 remove the outer bark of this species ; besides there would be much loss in the 

 process. 



The modern chromed hide-powder mctliod was that a(]o])(((l in these 

 analyses, the air-dried bark being somewhat linely ground. 



