CHLOROPHYL. 21 



glucose, is thus similarly able to bring about the synthetic formation 

 of maltose from two molecules of glucose. On the other hand, it 

 appears that the primary formation of food-stuffs in plants does 

 not occur in this manner, but is referable to the activity of a special 

 body which, as has been stated, is present in the exposed green 

 parts of most plants, and which is termed chlorophyl. This sub- 

 stance occurs widely distributed in the vegetable world, but is also 

 found in those low forms of animal life in which the processes of 

 nutrition are essentially the same as those met with in the higher 

 plants. Of the chemical composition and structure of chlorophyl 

 we know little that is definite. Numerous attempts have been made 

 to isolate it from the living plant, but it is doubtful whether any of 

 these attempts have yielded the actual substance. Only its decom- 

 position-products, or at best very impure forms, have apparently 

 been obtained. Gautier, it is true, claims to have isolated the sub- 

 stance in crystalline form by methods which are calculated to avoid 

 its chemical alteration. Others, however, have not been successful 

 in repeating his work. 



The substance which Gautier obtained from spinach-leaves oc- 

 curred in the form of small crystals of a dark-green color, which 

 on exposure to light turned brown, then yellow, and finally became 

 colorless. Its composition corresponded to the formula C 40 H 64 N 2 O 4 . 

 The mineral ash consisted of about 1.75 per cent, of magnesium 

 phosphate, traces of calcium and sulphates, while iron was absent. 

 Treated with hydrochloric acid, it was decomposed into phylloxanthin 

 and phyllocyanic acid, C^H M N 4 O fl or C^H^^Og. This latter is 

 thus a homologue of bttirubin, C^H^N^, which in turn is derived 

 from hsematin, and is isomeric with hcematoporphyrin. A most 

 interesting relationship between the blood coloring-matter haemo- 

 globin and the vegetable coloring-matter chlorophyl thus becomes 

 apparent, and constitutes a further link connecting the animal with 

 the vegetable world. Further investigations have shown that a 

 substance can be obtained from chlorophyl, which is termed phyllo- 

 porphyrin, and which differs from hsematoporphyrin anhydride 

 only in containing three atoms less of oxygen, viz., C 32 H 34 N 4 O 2 . 

 Both phylloporphyrin and hsematoporphyrin, yield the same 

 decomposition-product on reduction with phosphonium iodide and 

 hydriodic acid, viz., hsemopyrrol, C 8 B' 13 N ; and if the reduction of 

 hsematoporphyrin is not carried on too energetically mesoporphyrin 

 results (C 32 H 3f) N 4 O 4 ), which manifestly stands midway between 

 hsematoporphyrin and phylloporphyrin. 



Moderately concentrated solutions of chlorophyl in alcohol or 

 petroleum-ether show seven bands of absorption. The first of these, 

 I, is situated in the red portion of the spectrum between B and C, 

 and is well pronounced and sharply defined on both sides. The 

 bands II, III, and IV are rather indistinct and scattered through 

 the orange-yellow, the yellow and the yellowish-green portion be- 

 tween C and E. From F off, the greater portion of the spectrum 



