262 Dr Playfair on the Food of Man under 



of our enterprising countrymen having overcome all difficul- 

 ties, and returning home with a rich booty. 



The egg of the Great Auk (occasionally it lays two, as it 

 would seem from the foregoing) is about the size of that of a 

 swan, and in shape it resembles that of the Foolish Guille- 

 mot, but is less pointed. The ground colour is dirty white, 

 tinged with yellow, marked, especially at the thicker end. with 

 black-gray and brown blotches and streaks. — L.Lloyd's Scan- 

 dinavian Adventures, vol. ii., p. 495. 



On the Food of Man under different conditions of Age and 

 Employment. By Dr Lyon Playfair, C.B., F.R.S.* 



The author commenced by adverting to our very imperfect 

 acquaintance with the statistics of food. We are still igno- 

 rant regarding the quantity of the different proximate constitu- 

 ents of aliment necessary for man's sustenance, even in his 

 healthy and normal condition. If the question were asked — 

 How much carbon should an adult man consume daily \ — 

 there would be scarcely more than one reliable answer, viz., 

 that the soldiers of the body-guard of the Duke of Darmstadt 

 eat about 11 oz.f of carbon in the daily supply of food. 



If, again, the question were asked — How much flesh-form- 

 ing matter supports an adult man in a normal condition \ — 

 no positive answer could be given. Even, as respects the 

 relation between the carbon in the flesh-forming matter and 

 that of the heat-givers, we have no reliable information. It 

 is true that certain theoretical conclusions on this head have 

 been drawn from the composition of flour, but no real statis- 

 tical answer deduced from actual experience exists. 



When we inquire into the cause of our ignorance on 

 these points, it is found that the progress to knowledge is 

 surrounded with difficulties. Neither chemistry nor phy- 

 siology is in a sufficiently advanced state to grapple satis- 

 factorily with the subject of nutrition. For example, we 



* From the Proceedings of the Royal Institution of Great Britain in 1853. 

 t Liehig states a higher amount, hut this is a recalculation from the new 

 food tables. 



