Scientific Lectures. 115 



of alcoliol, and tlie other three by three molecules of the radical of 

 "wood spirit, a kind of alcohol. This remarkably complex body has 

 been found in the yellow of the egg, and in the blood corpuscles and 

 plasma, and in some grains. The discoverer called it protagon. As this 

 body is an important constituent of the brain, it occurred to me 

 that as the cliicken must derive the protagon of its brain from the 

 yolk of the egg, the calf must derive the protagon of its brain from 

 the milk of the cow, and I ought to find it in the oily constituent of 

 the milk, namely in the butter. I selected a fine sample of butter, 

 dissolved it in ether, leaving behind the salts of the milk and any 

 lingering casein and sugar of the buttermilk, and examined the ether 

 solution for phosphoric acid. My expectations were realized. I 

 found phosphoric acid. It was nataral now to look in the ethereal 

 extract of green grass and clover on which the cows feed. I did, and 

 found phosphoric acid. I then pushed my examinations to the green 

 leaves of vines, flowering plants, shrubs, fruit and ornamental trees, 

 and finding phosphoric acid everywhere in the ether extract of green 

 leaves, I came to the conclusion that phosphoric acid is a normal 

 constituent of chlorophyl as well as of butter. The chlorophyl of 

 the leaves has long been regarded as the chief seat of the agencies 

 which produce the vegetable organism, and no one can doubt the 

 important share the phosphoric acid plays in it. The advantage of 

 turning under a clover crop to give fertility to a soil seemed to have 

 a new explanation. So, too, tlie value of a compost of leaves, or 

 forest mould. The value of phosphatic fertilizers has long been 

 known. Kow, if phosphoric acid is so important to the vegetable 

 organism, it no longer surprises us tliat it is so universally present in 

 animal tissues and juices, and so essential a constituent of food. But 

 I must retm'n. 



SELE-LEAVEIS'mG FlODE. 



I found that phosphoric acid, by combining with it a small proj^or- 

 tion of lime, might be placed in a condition to have no affinity for 

 atmospheric moisture, and thus by diluting it with a dry powder, like 

 starch, it might easily be made pulverulent, and then as a powder 

 intimately mixed VN'itli flour. AV^hen, to this flour, bicarbonate of soda 

 was added, in quantities sufficient to neutralize the phosphoric acid, 

 and the whole was intimately mixed, tiiere was produced what might 

 be called self-raising or self-leavening flour. On stirring this prepared 

 flour with water, the phosphoric acid would dissolve and combine 

 "with the ssoda to liberate the carbonic acid and puff up the dough, 



