312 



SCIENCE, 



[Vol. VII., No. 165 



state. Double consciousness or triple consciousness 

 never occurs in healthy people, but only in the 

 hysterical, epileptic, insane, or in those who have 

 had severe shocks or injuries to the head. Dram- 

 atists and writers of fiction should bear this in 

 mind, if they wish to cling to the realities. 



Charles L. Dana, M.D. 



FOOD-ACCESSORIES: THEIR INFLUENCE 

 ON DIGESTION 



The results of experimental inquiries on the 

 subject of foods and food-digestion, when scientifi- 

 cally conducted, cannot help being of great practical 

 importance to man, so intimately is his physical 

 perfection and intellectual activity dependent upon 

 his alimentation. Among the results of certain 

 experiments on this subject by Sir W. Roberts, 

 as given in the Nineteenth century, the following 

 will be found of interest. 



Man, as the author says, is a very complex 

 feeder : he has departed, in the course of his 

 civilization, very widely from the monotonous 

 uniformity of diet observed in animals in the 

 wild state. Not only does he differ from other 

 animals in cooking his food, but he adds to his 

 food a greater or less number of condiments for the 

 purpose of increasing its flavor and attractiveness ; 

 but, above and beyond this, the complexity of his 

 food-habits is greatly increased by the custom of 

 partaking, in considerable quantity, of certain 

 stimulants and restoratives, such as tea, coffee, 

 cocoa, and the various alcoholic beverages, which 

 have become essential to his social comfort, if not 

 to his physical well-being. 



But the generalized food-customs of mankind 

 are not to be viewed as random practices adopted 

 to please the palate or gratify our idle or vicious 

 appetite. These customs must be regarded as the 

 outcome of profound instincts, which correspond 

 to important wants of the human economy. They 

 are the fruit of colossal experience, accumulated 

 through successive generations. They have the 

 same weight and significance as other kindred 

 facts of natural history, and are fitted to yield to 

 observation and study lessons of the highest scien- 

 tific and practical value. 



First, with respect to the action of ardent spirits 

 on digestion, experiments were made with k ] ^oof- 

 spirit,' and with brandy, Scotch whiskey, and gin ; 

 and the conclusion is, that, so far as salivary di- 

 gestion is concerned, these spirits, when used in 

 moderation and well diluted, as they usually are 

 when employed dietetic-ally, rather promote than 

 retard this part of the digestive process; and this 

 they do by causing an increased How of saliva. 



The proportion must not, however, much exceed 

 five per cent ; and gin seems to be less injurious 

 than either brandy or whiskey. It was noticed 

 in these experiments that both of these interfered 

 with the digestive process, precipitating the starch 

 more readily, altogether out of proportion to the 

 amount of alcohol they contained, and brandy 

 was worse than whiskey ; and this circumstance 

 appears to be due to certain ethers and volatile 

 oils in them; and brandy contains a trace of 

 tannin, which has an intensely retarding influ- 

 ence on salivary digestion. Even very small 

 quantities of the stronger and lighter wines — 

 sherry, hock, claret, and port — exercise a power- 

 ful retarding influence on salivary digestion. 

 This is due to the acid — not the alcohol — they 

 contain, and if this acid be neutralized, as it often 

 is in practice, by mixing with the wine some 

 effervescent alkaline water, the disturbing effect 

 on salivary digestion is removed. 



In the case of vinegar, it was found that 1 part 

 in 5,000 sensibly retarded this process, a pro- 

 portion of 1 in 1,000 rendered it very slow, and of 

 1 in 500 arrested it completely ; so that, when acid 

 salads are taken with bread, the effect of the acid 

 is to prevent any salivary digestion of the latter, 

 — a matter of little moment to a person with a 

 vigorous digestion, but to a feeble dyspeptic one 

 of some importance. There is a very wide-spread 

 belief that drinking vinegar is an efficacious 

 means of avoiding getting fat ; and this popular 

 belief would appear, from these experimental 

 observations, to be well founded. If the vinegar 

 be taken at the same time as farinaceous food, 

 it will greatly interfere with its digestion and 

 assimilation. 



Effervescent table-waters, if they consist simply 

 of pure water charged with carbonic acid, exer- 

 cise a considerable retarding influence on salivary 

 digestion ; but if they also contain alkaline car- 

 bonates, as most of the table-waters of commerce 

 do, the presence of the alkali quite removes this 

 retarding effect. 



With regard to ' peptic ' digestion, the results 

 are still more surprising. It was found that with 

 ten per cent and under, of proof -spirit, there was 

 no appreciable retardation, and only a slight re- 

 tardation with twenty per cent ; but with large 

 percentages it was very different, and with fifty 

 per cent the digestive ferment was almost para- 

 lyzed. It was also observed that the weaker 

 forms of alcoholic drinks (wines and beer) differed 

 greatly in the influence on peptic digestion from 

 that of the distilled spirits. They retarded it alto- 

 gether out of proportion to the quantity of alcohol 

 they contained. Port and sherry exercised a great 

 retarding effect. Even in the proportion of twenty 



