Predigested Foods.  The value of these is doubtful, for digestive disturbances involve the motor functions and absorption more commonly than the chemical functions.  Their continued use often produces irritation.

Liquid Predigested Foods.  As sold, these are flavoured solutions containing small amounts (1/2-6 per cent) of predigested proteins, 1/2-15 per cent of sugars and other carbohydrates, with 12-19 per cent of alcohol, and often with large quantities (up to 30 per cent) of glycerin.  Their protein content averages less than that of milk, and in energy value they are vastly inferior.  Their daily dose yields but 55-300 calories including their alcohol; this is only one-thirtieth to one-fifth the minimum requirements of resting patients.  To increase their dose to that required to maintain nutrition would mean the ingestion of an amount of alcohol equivalent to a pint of whisky per day.

Of recent years very expensive preparations of real or alleged organic iron compounds have had a large sale.  Iron is a component of haemoglobin, a solid constituent (13 per cent by weight) of the blood, which combines with the oxygen in the lungs, and is carried (as oxyhaemoglobin) all over the body, giving the oxygen up to the tissues.  Haemoglobin is an exceedingly complex substance, but it contains only one-third per cent by weight of iron in organic form.

The liver is the storehouse of iron, its reserve being depleted when there is an extraordinary demand for iron.  The minute amounts of iron in ordinary food are amply sufficient for all our needs; any excess is simply stored, and, later excreted, and has no effect whatever on the circulating haemoglobin.

Iron is only of value in certain forms of anaemia, and the many patent medicines purporting to contain haemoglobin or organic iron are therefore useless to neuropaths.  The Roman plan of drinking water in which swords had been rusted, is quite as valuable as drinking expensive proprietary compounds.  When iron is indicated Blaud’s Pills are perhaps the best preparation.

Huge quantities of patent medicines containing phosphates in the form of hypo-or glycerophosphates, and (or) lecithin are sold annually.

All phosphorus compounds are reduced to inorganic phosphates in the digestive tract, absorbed and eliminated, so that, as with iron, if phosphates are needed, the form in which they are taken is of no moment.  Why, then, pay huge sums for organic-phosphorus compounds (synthesized from inorganic phosphates) when they are immediately reduced to the same constituents from which they were constructed, the only value in the reduction process being seen in the immense fortunes which patent-medicine proprietors accumulate?

Lecithin is isolated from animal brain, or egg-yolk, and commercial lecithin is impure.  Not only does the ordinary daily diet contain ample lecithin (5 grammes), but two eggs will double this, while liver or sweetbread, both rich in phosphorous, may be eaten.