434 THE MANGOLD-WURZEL CHOP. 



able also that the experiment should be made in different 

 districts of the country, and with the different varieties 

 of mangold ; and that the method of stripping practised so 

 successfully on the Albert Model Farm should be followed 

 as closely as possible. If the increased produce promised 

 is confirmed, it would then be desirable to see how far Dr. 

 Wolff's theory of depreciated feeding value is sustained, 

 as we know, from our own investigations into the compo- 

 sition of turnips (page 327), that an increased bulk of 

 produce does not necessarily indicate an increased amount 

 of food. The supply of leaves is no doubt of value to 

 the farmer, especially coming as they do at the period of 

 the season when the grass is always short, and the root 

 crops not sufficiently advanced to be available as keep ; 

 their real food value has, however, probably been over- 

 rated, as we have reason to believe that a considerable 

 part of the nitrogen they contain exists in the shape of 

 ammonia, and not of those compounds (flesh-formers) upon 

 the proportion of which we are accustomed to base our 

 estimates of the food value of different substances. 



Dr. Wolff's experiments would show that at all events 

 they are not very valuable for dairy purposes. 



The milk produce of three cows was submitted to exa- 

 mination. In the first experiment they were fed princi- 

 pally on aftermath; in the second this was replaced by 

 mangold leaves : 



Experiment A. Fed on Aftermath. 



l. 2. 3. 



Dry substances in milk, 12'47 12'49 11.-89 



Water in milk, 87'58 87'51 88'62 



Butter 3-13 3'39 2'53 



Experiment B. Fed on Mangold Leaves. 



1. 2. 3. 



Dry substances in milk, 11-30 12'08 11'04 



Water in milk, 8870 87'42 88'96 



Butter 2-60 2'88 2'20 



These results show a considerable deterioration in the 



