264 Dr Playfair on the Food of Man under 



respirations, the rapidity of the pulsations, and the relative 

 capacity of the lungs. Cold increases the number of respira- 

 tions and heat diminishes them ; and the lecturer cited well- 

 known cases of the voracity of residents in Arctic regions, 

 although he admitted, as an anomaly, that the inhabitants of 

 tropical climates often shew a predilection for fatty or car- 

 bonaceous bodies. He then drew attention to the extra- 

 ordinary records of Arctic dietaries shewn in the table, which, 

 admitting that they are extreme cases, even in the Arctic 

 regions, are nevertheless very surprising. 



Dr Playfair then alluded to the second great class of food 

 ingredients, viz., those of the same composition as flesh. 

 Beccaria, in 1742, pointed to the close resemblance between 

 these ingredients of flesh, and asked, "Is it not true that we 

 are composed of the same substances which serve as our 

 nourishment 1 " In fact, the simplicity of this view is now 

 generally acknowledged ; and albumen, gluten, caseine, &c, 

 are now recognised as flesh- formers in the same sense that 

 any animal aliment is. After alluding to the mineral ingre- 

 dients, attention was directed to a diet-table, which contained 

 some modifications, but was based on the one published in 

 the Agricultural Cyclopaedia under the article Diet; the 

 table as shewn being used in the calculation of the dietaries. 



The old mode of estimating the value of dietaries, by 

 merely giving the total number of ounces of solid food used 

 daily or weekly, and quite irrespective of its composition, 

 was shewn to be quite erroneous ; and an instance was given 

 of an agricultural labourer in Gloucestershire, who in the 

 year of the potato famine subsisted chiefly on flour, consum- 

 ing 163 ounces weekly, which contained 26 ounces of flesh- 

 formers. When potatoes cheapened he returned to a potato- 

 diet, and now ate 321 ounces weekly, although his true 

 nutriment, in flesh-formers, was only about 8 or 10 ounces. 

 He shewed this further, by calling attention to the six 

 pauper dietaries formerly recommended, to the difference 

 between the salt and fresh meat dietary of the sailor, &c, 

 all of which, relying on absolute weight alone, had in reality 

 no relation in equivalent nutritive value. 



Attention was now directed to the diagrams exemplifying 



