Schunck . — The Chemistry of Chlorophyll. 81 
Berzelius 1 and Mulder 2 , it will be found that they employed 
concentrated hydrochloric acid as a means of purifying chloro- 
phyll ; it is evident therefore that they worked with a product 
or products of decomposition, not with unaltered chlorophyll. 
Berzelius describes three modifications of chlorophyll obtained 
by him from green leaves, though with regard to one of them 
he admits that it may have been the product of chemical 
treatment, and not really have pre-existed in the plant. As 
regards chlorophyll on the whole, however, Berzelius asserts 
that it is not destroyed either by acids or alkalis, but rather 
combines with them in definite proportions. Much here 
depends on the meaning of the word ‘destroy’; the colour 
of chlorophyll is certainly not destroyed by hydrochloric or 
sulphuric acid, it is rather heightened by an excess of either of 
these acids ; but an examination of the spectrum of chlorophyll 
before and after treatment with acid would have shown that a 
change had taken place. It was the mere similarity in colour 
that led Berzelius to suppose that the biliverdin of bile was 
identical with chlorophyll. According to Professor Stokes, the 
two substances are totally distinct, the solution of biliverdin 
showing none of the absorption-bands peculiar to chlorophyll. 
The memoir of Berzelius on chlorophyll contains, however, 
some observations which are still of some interest, and to which 
I shall refer hereafter. By the combined action of ether and 
hydrochloric acid on chlorophyll Fremy obtained two colouring 
matters, a blue and a yellow one. Since some doubt has 
been expressed with regard to the conclusions to which he 
was led by his experiments, I think it best to describe what 
he observed in his own words. He says, ‘Voulant done 
separer les deux matieres colorantes qui donnent a la chloro- 
phylle sa couleur verte, j’introduis dans un flacon un liquide 
compose de % parties d’ether et i partie d’acide chlorhydrique 
etendu d’une petite quantite d’eau ; j’agite fortement le flacon 
de maniere a saturer l’acide chlorhydrique d’ether. En 
1 Annalen d. Pharm. XXVII. 296. 
2 Journ. f, Pract. Chemie, XXXIII. 478. 
G 
