Among the seemingly radical suggestions that have lately found expression in discussions on nutrition is that of the possible utilization of such simple compounds of nitrogen as urea and ammonium salts in the animal organism. Even the nitrates have been drawn into consideration in this respect. The entire subject, while by no means entirely new as a topic for experiment and speculation in physiology, has more recently provoked a lively controversy in which Abderhalden in Halle, Grafe in Heidelberg, and Underhill in New Haven — to mention only a few of the more prominent participants — have taken an active part.
At first thought, those who have not followed at close range the trend of current nutrition investigation might see in the attempt to attribute nutrient virtues to a waste product like urea a symptom of ridiculous presumption. Nowadays, however, science does not content itself with a priori indications or