TRANSACTIONS OF SECTION B. 689 



which B. is any element or group of elements, whilst A, B, C, &c, are elements 

 belonging to the same subgroup of Mendleljeff's classification of the elements. 



Tables accompany the paper in illustration of the above. 



Out of 426 cases, in which the third of the above rules has been applied, there 

 are but sixteen exceptions, or less than 4 per cent. 



Finally, a theoretical explanation is given, which appears to account in a verv 

 simple manner for the influence of the above three circumstances, on the colour of 

 chemical compounds. 



7. Preliminary Notes on a Blue-colouring matter found in certain wood 

 undergoing decomposition in the forest. By Professor G. P. Giedwood 

 M.D., and, J. Bemrose, F.O.S. 



The wood, the origin of these remarks, was found in numerous pieces in travel- 

 ling through the forests, but could never be found in such large pieces as to be 

 capable of identification, the bark being absent in all cases, and the wood moss 

 grown ; several knots and fragments of roots leading to the supposition (borne out 

 "by the microscopical characters) that it is from the balsam pine (Abies balsamea). 

 All specimens have been found lying on the ground ; never in standing trees. 



The blue-colouring matter has been observed in the junction between the heart 

 wood and the sap wood ; it seems to percolate or be absorbed by the sap wood 

 more freely than the heart wood. It is frequently developed between the laminae 

 of the roots to such an extent that it becomes almost submetallic in lustre, like 

 indigo. 



In making sections of the wood, and examining these under the microscope, the 

 wood thus far has been found to possess the pitted tissue peculiar to coniferous 

 trees, confirming the opinion that the tree is the balsam pine. The colour is found 

 in the material within the cell, and not in the cell wall. 



We have acted on the wood with the following reagents and obtained the 

 results mentioned : — 



"W ater . , .a dirty yellow solution . leaving on evaporation a 



brown residue. 



Alcohol . . .a pale coloured green solu- 

 tion in time , , leaves a brown residue 



on evaporation. 



TSther ...... dirty yellow a dirty brown residue. 



Benzol a pale yellow solution. 



Petroleum Spirit . . colourless. 



Boiling White Vaselin no action. 



Melted Paraffin . . no action. 



Carbolic Acid . . . dissolves out blue colour. 



Amylic Alcohol . . dark greenish blue solu- 

 tion, being part of co- 

 louring matter. 



Chloroform .... deep blue solution, dis- 

 solves out the whole of 

 the colouring matter. 



Wood treated successively with excess of water, H 2 0, alcohol, 0„H B 0, ether, 

 UH ]0 O, amylic alcohol, C.H^O, and then exhausted with chloroform, CHC1 



Ihe chloroform solution evaporated yielded the colour in scales with a slight 

 submetallic lustre. ° 



Blue colour treated with HN0 3 sp. gr. 1-42, dissolved, and evaporated without 



change. 



" >> » H 2 S0 4 dissolved, precipitated on dilution. 



» » » H 8 S0 4 x K 2 Cr 2 7 , reduced Cr0 3 to Cr 2 3 . 



■a » ,, H 3 P0 4 no change. 



» » t , A dissolved without apparent change. 

 1884. y y 



