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A Series of Experiments 07i the Qitantity of Food^ taken by a 

 Person in Healthy compared with the Quantity of the differ- 

 ent Secretions during the same period ; zvith Chemical Re- 

 marks an the several articles. By John Dalton, F. R. S. 



UuRiNG my residence at Kendal, nearly forty years ago, I had 

 at one time an inclination to the study of medicine, with a view 

 to future practice in the medical profession. It was on this ac- 

 count chiefly, but partly for my own personal interest in know- 

 ing the causes of disease and of health, that I v/as prompted to 

 make such investigations into the animal economy, as my cir- 

 cumstances and situation at the time would allow. I had met 

 with some account of Sanctorius's weighing chair, and of his 

 finding the quantity of insensible perspiration compared with 

 the quantity of aliment ; and it occurred to me, that the differ- 

 ences of constitution and of climate might occasion very conside- 

 rable modifications, which it would be desirable to ascertain. 

 The following train of experiments was accordingly instituted 

 for the purpose. 



It may be proper to observe, that my habits, daily occupa- 

 tions, and manner of living, were exceedingly regular ; my 

 health during the time was uniform and good ; and that the 

 weight of my person has never been subject to much change 

 since grown to maturity. 



The first series of experiments was made in the month of 

 March, for fourteen days successively. I had three meals each 

 day, breakfast between seven and eight in the morning, din- 

 ner between twelve and one, and supper about seven in the 

 evening; except on two days in which I had tea to breakfast, 

 and again in the afternoon. The usual breakfasts consisted of 

 boiled milk, with bread, and a little oat-meal, and suppers were 

 of the same, with the addition of bread, cheese, and beer. The 

 dinners consisted of butcher-meat, potatoes, pies, puddings, and 

 cheese. About one-third part of the bread used consisted of a 

 thin oat-cake, common in Westmoreland and Cumberland. I 

 drank no water, seldom wine, and no fermented liquor, except 

 common table-beer. 



