This increase in the quantity of the digestive fluid, due to nervous stimulus, is undoubtedly more than sufficient to make up for the alleged impairment of its quality caused by mixing it with a foreign substance. The action of saliva and carbonate of soda supply us with a further illustration. In artificial experiments, like those upon which Mr. Parton relies, alkaline substances are found to retard digestion by neutralizing a portion of the acid of the gastric juice. Yet the alkaline saliva, swallowed with food, does not retard digestion; and Claude Bernard has shown that carbonate of soda actually hastens, to a notable degree, the digestive process. Why is this? It is because these alkalies act as local stimulants upon the lining of the stomach, and thus increase the quantity of gastric juice. It is in this way that common salt, eaten with other food, also facilitates digestion; although salt is a _preserver_, as well as alcohol. [9] This is not always true, however: it is well to look sharp before making a sweeping statement. The digesting power of gastric juice is _increased_ by diluting it with a certain amount of water. See Lehmann, _Physiologische Chemie_, II. 47. Here we come upon Mr. Parton's second blunder. He talks about the "decomposition" of food, and appears to think that digestion is a kind of _putrefaction_, so that alcohol, which arrests the latter, must also arrest the former. He says: We do not need to experiment, for we _know_ that alcohol, which is a _preserver_, cannot digest food by decomposing it. This unlucky remark illustrates the danger of writing on a subject, the rudiments of which you have not taken time to get acquainted with. Before attempting to lay down the law upon an abstruse point connected with the subject of digestion, common prudence would appear to dictate that one should first acquire some dim notion of what digestion is. The veriest tyro in physiology should know that the gastric juice is itself a preventer of putrefaction. It will not only keep off organic decay, but it will stop it after it has begun.[10] In this sense of the word, it is as much a _preserver_ as alcohol. [10] Dunglison, _Human Physiology_, vol. I. p. 148; Lewes, _Physiology of Common Life_, vol. I. p. 170. As it takes time to expose all the fallacies which Mr. Parton can crowd into one short paragraph, we have thus far admitted that alcohol impairs the quality of the gastric juice by diluting it: as a matter of fact, it does not so impair it. If it is a _preserver_, it is also a _coagulator_. It coagulates the albuminous portions of the food, thus enabling them to be more easily acted upon by the gastric secretion.[11] So that, on looking into the matter, we find the stimulant dose of alcohol doing everything to quicken, and nothing whatever to slacken, digestion. It coaxes out more digestive fluid, and it lightens the task which that fluid has to perform. [11] Dunglison, op. cit. I. 196.