PRESERVATION OF HEALTH. 



Man designed to live on a Mixed Diet. 

 The followers of Pythagoras argued, from the 

 cruelty of putting animals to death, that it was 

 proper to live on vegetables alone ; and eccentric 

 persons of modern times have acted upon this rule. 

 But the ordinances of Nature speak a different 

 language ; and if we have any faith in these, we 

 cannot for a moment doubt that a mixture of 

 animal food is necessary for our well-being. On 

 the other hand, we cannot dispense with vegetable 

 food without injurious consequences. In that case, 

 we place in a medium alimentary canal a kind of 

 food which is calculated for a short one, thus 

 violating an arrangement of the most important 

 nature. A balance between the two kinds of food 

 is what we should observe, if we would desire to 

 live a natural and healthy life. 



Rules connected with Eating. 



In order fully to understand how to eat, what to 

 eat, and how to conduct ourselves after eating, it 

 is necessary that we should be acquainted in some 

 measure with, the process of nutrition that curious 

 scries of operations by which food is received and 

 assimilated by our system, in order to make good 

 the deficiency produced by waste. 



Even in the introductory stage there are certain 

 rules to be observed. Strange as it may appear, 

 to know how to eat is physiologically a matter 

 of very considerable importance. Many persons, 

 thinking it all a matter of indifference, or perhaps 

 unduly anxious to despatch their meals, eat very 

 fast. If we are to believe the accounts of travellers, 

 the whole of the mercantile classes in the United 

 States of America eat hurriedly, seldom taking 

 more than ten minutes to breakfast, and a quarter 

 of an hour to dinner. They tumble their meat 

 precipitately into their mouths, and swallow it 

 almost without mastication. This is contrary to 

 an express law of nature, as may be very easily 

 demonstrated. 



Food, on being received into the mouth, has 

 two processes to undergo, both very necessary to 

 digestion : it has to be masticated, or chewed 

 down, and also to receive an admixture of saliva. 

 The saliva is a fluid arising from certain glands in 

 and near the mouth, and approaching in character 

 to the gastric juice afterwards to be described. 

 Unless food be well broken down or masticated, 

 and also well mixed up with the salivary fluid, it 

 will be difficult of digestion. The stomach is then 

 called upon to perform, besides its own proper 

 function, that which properly belongs to the teeth 

 and saliva, and it is thus overburdened, often to 

 a very serious extent. The pains of indigestion 

 are the immediate consequence, and more remote 

 injuries are likely to follow. 



The importance of the saliva has been shewn in 

 a striking manner on several occasions when food 

 was received into the stomach otherwise than 

 through the mouth. A gentleman, who, in conse- 

 quence of a stricture in the gullet, had his food 

 introduced by an aperture into that tube, used to 

 suffer severely from indigestion. It is recorded of 

 a criminal, who, having cut his throat in prison 

 without fatal consequences, required to get his 

 food introduced by means of a tube inserted by 

 the mouth, that every time he was fed there was 

 an effusion of saliva to the amount of from six to 

 eight ounces. We cannot suppose that a fluid of 



a peculiar character would have been prepared in 

 such quantity, when water would serve as well 

 merely to moisten the food, if it had not been 

 designed to act an important part in the business 

 of nutrition. 



With regard to mastication, the evidence of its 

 importance is still more decided. Some years 

 ago, a young Canadian, named Alexis St Martin, 

 had a hole made by a shot into his stomach, which 

 healed without becoming closed. It was therefore 

 possible to observe the whole operations of the 

 stomach with the eye. His medical attendant, Dr 

 Beaumont, by these means ascertained that when 

 a piece of solid food was introduced, the gastric 

 juice acted merely on its outside. It was only 

 when the food was comminuted, or made small, 

 that this fluid could fully perform its function. 

 When the stomach finds itself totally unable to 

 digest a solid piece of food, it either rejects it by 

 vomiting, or passes it on into the gut, where it 

 produces an irritating effect, and is apt to occasion 

 an attack of colic or flatulency. It must therefore 

 be concluded, that a deliberate mastication of our 

 food is conducive to health, and that fast eating is 

 injurious, and sometimes even dangerous. 



The food, having been properly masticated, 

 is by the action of the tongue thrown into the 

 gullet. It then descends into the stomach, not so 

 much by its own gravity, as by its being urged 

 along by the contractions and motions of the 

 gullet itself. The stomach may be considered as 

 an expansion of the gullet, and the chief part of 

 the alimentary canal. It is, in fact, a membranous 

 pouch or bag, very similar in shape to a bagpipe, 

 having two openings, the one by which the food 

 is admitted, the other that by which it is passed 

 onward. It is into the greater curvature of the 

 bag that the gullet enters ; at the lesser, it opens 

 into that adjoining portion of the canal into which 

 the half-digested mass is next propelled. 



When food has been introduced, the two orifices 

 close, and that which we may term the second 

 stage in the process of digestion commences. 

 The mass, already saturated with saliva, and so 

 broken down as to expose all its particles to the 

 action of the gastric juice, is now submitted to 

 the action of that fluid, which, during digestion, 

 is freely secreted by the vessels of the stomach. 

 The most remarkable quality of this juice is its 

 solvent power, which is prodigious. 



The food exposed to this dissolving agency is 

 converted into a soft, gray, pulpy mass, called 

 chyme, which, by the muscular contraction of the 

 stomach, is urged on into the adjoining part of 

 the alimentary canal, called the duodenum. This 

 is generally completed in the space of from half 

 an hour to two or three hours ; the period varying 

 according to the nature and volume of the food 

 taken, and the degree of mastication and insaliva- 

 tion it has undergone. 



In the duodenum, the chyme becomes inti- 

 mately mixed and incorporated with the bile and 

 pancreatic juices ; also with a fluid secreted by 

 the mucous follicles of the intestine itself. The 

 bile is a greenish, bitter, and somewhat viscid 

 fluid, secreted by the liver, which occupies a con- 

 siderable space on the right side of the body 

 immediately under the ribs. From this organ the 

 bile, after a portion of it has passed up into the 

 adjacent gall-bladder, which serves as a reservoir, 

 descends through a small duct, about the size of 



m 



