ON THE GROWTH AND VITALITY OP SEEDS. 
145 
of tliese differences. When a small quantity of linio is added to the brown 
precipitate, it combines exclusively with the rubiaciu, or is transferred during 
the process of dyeing exclusively to the rubiacin. The first effect of the 
dyeing is the combination of the alizarin %vith the alumina and peroxide of 
iron of the mordant-!. These compoutidfi then attract and coiubiiie with the 
lime compound of rubiacin contained in the fluid, by wbieli means a greater 
mtensity of colour is jiroduced. 1 repeated this oxptwimeiit with the pure 
colounjig matters. I took two pieces of Uionlanfcd cloth of the same size, 
and dyed the one with pure alizarin, and the other with the same nuaiititv of 
fjizann to which rubiacin combined with lime was uddeil, and 1 found that 
the latter ^ much darker than the former. I tlu-reforc conclude that 
madder flours arc always double compounds of alizarin, rnbiadii, alumina, 
fine base ” alizarin, rubiacin, poroxitle of iron, and an alka¬ 
li follows from tliis that the maximum of tinctoriul power in madder is 
pruduced when the alizarin is in a free state, and the rubiacin is in coinbi- 
uation with lime or some alkaline base. If an excess of lime be added then 
the ahzanu also combines with it, and is (bus rendered incapable of attaching 
tteelf to the alumina and poi-oxide of iron of the mortlants. A slight excess 
0 loie exist? in the root when grown on a calcareous soil; for if a quantity 
madder which has dyed as much cloth as it is capable of doing and is 
minglrquite exhausted of colouring matter, bo treated with sulphuric acid, 
^ carefully removed by washing, it is found that aAcr being so 
did w'^ capable of again dyeing almost as much mordanted cloth as it 
I “ *®ct long known in practice. I may state in addition, that the 
has P^*iced by the brown precipitate to which a stnall quantity of lime 
resist the action of soap and acids, ^cc., to w’hich all madder 
liii.p r ®i'*liccted in order to lifigliteu them, much better than if no 
Cfn'i-«r r ^ tliereforc conclude, that though the possibility in 
oycing with madder is due to alizarin, the solidity and brilliance 
w mauder coloum must be ascribed to rubiacin. 
of a Commitiee, cotmsHnff of 11. E. Strickland, Esg., 
Prof. Henslow, and Prof. Li.vdley, aiyimnttd 
thnr Experiments on the. VitulUy of Seeds. 
second sowing of the seeds collected in 1837 and 
hareb addition to these, ten kinds of new seeds gathered in 1846 
These w'ere the entire number available for the purpose, 
^orrer- * great quantity presented by Miss Molesworth, of Cobliam, 
sufficient ^ ’^uimler consisted of kinds previously tested, or were not in 
her Jn.H. for general distribution or preservation, atid according to 
^ '“^truclioDs were sown in the Oxford garden *. 
these si>^,le xrs.. it-i........ 
L 
