FIFTY-SECOND ANNUAL CONVENTION 37 



eries in stock feeding and their practical application. Rob- 

 ert Burns wrote : '*A man's a man for a' that and a' that." 

 Now that is exceedingly good poetry but mighty poor horse 

 sense as you all know and will agree, because men differ 

 radically in their capabilities, in their training and in their 

 integrity. I don't need to discuss that further. I merely 

 want to point out the fact that the different proteins fed 

 differ as much as men do in efficiency and in quality. 



Proteins are the most complicated of all of the feeds 

 which an animal consumes, undoubtedly. Let me illus- 

 trate just how complicated they are. Any of you who have 

 had any chemistry know that the chemical formula for 

 water is H'O. That means that one molecule, the simplest 

 particle of water, contains two atoms of hydrogen and one 

 of oxygen. Then there is NaCl. Compared with those 

 very simple substances the best chemists who have been 

 working on the composition of proteins tell us that the 

 simple protein molecule contains all the way from three 

 or four thousand up to ten thousand atoms of milk casein. 

 According to the most recent investigations a single mole- 

 cule of milk casein apparently contains about one hundred 

 thousand atoms. Do you blame the chemists for not know- 

 ing all about the composition of proteins? Think of a sin- 

 gle particle of casein containing one hundred thousand 

 atoms arranged in an intricate pattern. All a chemist can 

 tell us about proteins is by means of experiments where 

 they tear the patterns all to pieces by the action of strong 

 alkali or strong acids, and break the proteins down and 

 study the fragments of which they are composed. It would 

 be a great deal as though a cyclone or tornado demolished 

 this building, and then looking at the fragments left on the 

 ground it would take a very vivid imagination to tell some- 

 thing about the architecture of the building. 



About all we know with reference to the composition 

 of proteins is that the proteins of feeding stuffs and those 

 which make up our bodies are made up of from eighteen 

 to twenty different building stones or amino acids. I shall 

 use some scientific and technical expressions this morning 

 and this afternoon, and I am not going to apologize for so 



