8 



Prof. A. J. Ewart, 



flasks (A and B) containing 40 c.c. of dilute formaldehyde, one also contained 

 a film of 01 grm. of chlorophyll (A). When this was bleached the filtrates 

 were evaporated to dryness on a water-bath, weighed, and then further heated 

 to drive off the paraformaldehyde. 



The final dry residue from A gave a strong reduction with Fehling's test. 

 Since the bleached residue in A still weighed 0'085 grm., there is apparently 

 evidence here of a feeble polymerisation of formaldehyde by chlorophyll. 



The Solid Products of the Photo-oxidation of Chlorophyll, Carotin and 



Xanthophyll. 



In all three cases the solid residues consist of a portion soluble in water, 

 and of a white waxy solid insoluble in water but melting when heated. 

 The latter appears to consist, in the case of carotin, partly at least of phyto- 

 sterin.* 



The white insoluble residue from the bleaching of chlorophyll is a waxy 

 solid with a smell of beeswax. In one experiment - 4 grm. yielded 1'99 per 

 cent, of magnesium oxide (pure chlorophyll should yield 4*5 per cent.), so that 

 apparently after decomposition some of the magnesium can be removed by 

 washing with water. The white " chlorophyll wax " melts gradually on 

 warming, like sealing wax, beginning about 80° C, and is rather brittle in 

 mass when cold. Possibly it consists of a mixture of substances. It dissolves 

 readily in hot alcohol, very sparingly in cold alcohol, and is moderately soluble 

 in petrol ether. 



The watery extract from fully bleached chlorophyll contains no aldehydes. 

 It has a bitter taste, turns turbid on boiling or on adding copper sulphate, 

 but becomes clear on adding sodium hydrate, and gives a strong reduction 

 with Fehling's test. On warming with a drop of sulphuric acid, the white 

 precipitate thrown down forms an oily solid clinging to the tube, and on 

 filtering the clear solution gives a strong reduction with Fehling's test. In 

 one experiment 0'61 grm. of chlorophyll yielded - 64 grm. of dry bleached 

 residue after full oxidation in moist air deprived of carbon dioxide, of which 

 0*23 grm. was removed by cold water, and 0'41 grm. remained as an insoluble 

 film. If the film is properly prepared and the contact with water made 

 gradually, none of the film breaks away from the glass or mica. 



The tendency to turbidity on the part of the watery extract prevents 



A 

 B 



First dry residue. Final dry residue. 

 .... 1-24 0-15 

 .... T25 0-052 



* See Czapek, ' Biochemie der Pflanzen,' p. 172. 



