22 THE VITAMINES 



lived 11 days; the others, 13, 14, 15 and 21 days, respectively, while 

 starving animals lived only from 3 to 4 days. The addition of soda, 

 which served the purpose of neutralizing the sulphuric acid arising 

 from the protein cleavage prolonged the life of the animals to a 

 certain extent; the ash of milk likewise had the same effect. Lunin 

 explained the results as being due to a lack of organic phosphorus 

 compounds (lecithin), and to a disturbance in the balance between 

 the inorganic and organic food components. Subsequently, Lunin 

 made the unusually important observation that mice could thrive 

 very well on milk powder even after two and a half months, and 

 therefore concluded that milk contained besides the known elements, 

 other unknown substances essential to life. That this conclusion 

 had already been arrived at in 1881 must appear to us as truly 

 remarkable. 1 Socin (11), working in the same laboratory, also came 

 to a similar conclusion in 1891. His problem required him to find 

 out whether inorganic or organic iron is the better utilized in the 

 animal body. Mice were kept on a diet consisting of blood serum, 

 fat, sugar, starch, cellulose and ash (obtained from milk). The 

 missing iron was added in the form of hemoglobin, hematin, or iron 

 chloride, without the least effect being apparent on the duration of 

 life. All of the animals died after 32 days, while the controls, fed 

 on yolk of egg, starch and cellulose, were still alive after 99 days. 

 Bunge (12) himself obtained the same results. Hausermann (13), 

 working with rats, guinea pigs, rabbits, cats and dogs, kept on white 

 bread and rice, could see an improvement after the addition of iron, 

 although a normal state of nutrition could not be brought about. 

 The experiments of Socin were confirmed by Hall (14) and 

 Coppola (15). 



Considering simple feeding experiments, we find the work of 

 Pasqualis (16) on chickens, receiving a diet composed of 14 per cent 

 protein, 65 per cent corn starch, 4 per cent dextrin, 4 per cent sugar, 

 9 per cent olive oil, 2 per cent wood chips, 1 per cent common salt 



1 Lunin concluded that "mice can live well under these conditions when 

 receiving suitable foods (milk) but as the above experiments demonstrate 

 that they were unable to live on proteins, fats, carbohydrates, salts and water, 

 it follows that other substances indispensable for nutrition must be present 

 in milk besides casein, fat, lactose and salts." This conclusion was quoted 

 in Bunge's Physiological and Pathological Chemistry, but did not attract 

 the attention it merited. 



