







I 





IN VEGETABLE BIOLOGY. 



513 









Millon's fluid. 



One might perhaps, considering this colour- 





difference and considering too the way in which the bright hue 

 of the stoppers flies if boiling be continued — a peculiarity, 



however, which 



is shared by the cell-protoplasm — one might, 











perhaps, regard the crimson of the stoppers with suspicion, the 

 normal colour for proteids being more or less of a brick-red. 

 But it must be remembered that there is much variation in this 

 respect even among typical proteids ; thus Krasser * gives the 



followi 



mg instances of this fact : 









v 



» 



carmine. 







Albumen takes a flesh-red. 



Fibrin 



Legumin 



Vitellin 



flesh-red to brown-red. 

 brick-red. 











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The real reason for the bright colour I believe to be that the 

 stoppers consist of densely aggregated matter and so would 

 necessarily be highly coloured ; and this idea is sustained by an 

 already mentioned fact, viz. the deeper hue taken by the more 

 densely aggregated parts of the protoplasm. 



Copper Sulphate and Caustic Potash also act very well j the 

 effect is usually got within a few minutes. The colour is usually 

 a pale dirty pink, but sometimes it is pale blue ; the former is 

 not a good colour for a proteid, it is admitted, but precisely the 

 same colour is taken by the cell-protoplasm. 



MaspaiVs reaction (Sugar and Sulphuric Acid) succeeds very 

 fairly— the colour is a pale brown-pink ; the protoplasm behaves 

 similarly. 



I have not tried Krasser's t Alloxan reaction, since Klebs % has 

 shown it to have no value in the detection of proteids. Neither 

 has AdamKiewicz's test been resorted to (violet colour with 

 glacial acetic acid and strong hydric sulphate), for this is said to 

 give too pale a colour to be appreciable under the microscope. 

 There is just a chance, however, in view of the brilliant colour 



anthoproteic and Millons 



reactions, that AdamKiewicz's test might succeed with the 

 stoppers. 





«J ~ ~~" "7 - ' 



taken by the stoppers with the s 









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Sitzb. d. Wien. Akad. Band 94. 

 I Bot. Zeitung. 1887. 



t Krasser, I. e. 







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