Letter from the Author to the "Daily Telegraph," published during the prevalence of Typhus Fever in the Metropolis, to call attention to the mischief which may accrue from neglecting even one of the essentials of a normal diet.

Sir, - The folly of the man who built his house upon the sands is familiar to all the world; but there is a parable of a folly even greater than his. A people, knowing that a tempest was approaching, left out the mortar and the girders from the houses they were building, and when the tempest came, and the winds blew upon the houses, they crumbled to pieces before the storm.

It will hardly be believed that such an act as this is being performed, at the present hour, in the most enlightened city of Christendom, under the eyes of scientific and learned men, in the purest innocence and good faith, and in the name of charity. Yet such is the plain truth.

Typhus fever has made its appearance in the houses of the half-starved poor of this metropolis. It is a contagious disease, but requires a particular soil to insure its fructification. Hence, out of any number of persons exposed to its poison, those suffer from the disease whose bodies present the most appropriate soil, and it proves especially fatal to those who are most strongly predisposed to its attack. It is well known to pathologists that in those who die of typhus all the tissues of the body, and the blood itself, are found to have lost their plasticity. Loss of plasticity in the body, and general want of vital force, constitute the characteristics of the soil in which the seed of typhus is sure to fructify. It would seem, then, but the most obvious common sense, that wherever the seed of typhus is known to be lurking every possible effort should be made to secure that it shall find no appropriate soil - that no human bodies deficient in plasticity shall be at hand. Yet what is the real state of the case? Typhus fever follows in the track of want. It fixes on some household where the effects of want are rife - i.e., where the inmates are reduced to the last extreme of poverty, and as a consequence are depending upon parish relief. Such a household is almost sure to be closely associated with others of the same class - depending upon parish relief. This parish relief means bread.

The seed of typhus, then, is scattered amongst a community subsisting upon bread. Now the houses in the parable, built up without mortar or girders, are the analogues of the human bodies, built up out of bread. They have lost plasticity, and when the seed of typhus falls upon them, it takes root and fructifies, and they crumble to pieces before the storm of sickness. It is hardly possible to maintain the body in health upon bread alone. A long study of the composition of food, in relation to health, warrants me in making this assertion; and I feel bound, in the cause of humanity, to call attention to this fact at the present moment, when the winter is at hand, and the poor of this city are threatened with such a scourge as typhus fever.

No food can maintain health in an adult, unless the average allowance for twenty-four hours yields to analysis from 3 to 4 oz. of plastic material, from 2 to 3 oz. of fat, and from 8 to 10 oz. of saccharine material. (See Essentials of a Normal Diet.) Compare this with the composition of bread. At least 32 oz. of bread must not only be eaten but assimilated in order to obtain 3 oz. of plastic material, the smallest amount which can be accepted as necessary to supply the daily waste of tissue. This assimilation cannot take place without a certain proportion of fat, which fat is not supplied in the necessary quantity by the bread, and no other source of supply is provided by the parish relief. It thus becomes evident that all those poor creatures who are entirely dependent upon bread for their existence, are specially prepared for the reception of typhus, and not less specially prepared for its fatal issue.

Setting every other consideration aside, then, and taking simply the ground of economy, it is a frightful extravagance of the funds of a parish, not less than of its life, to issue rations of bread only to the inhabitants of districts where typhus fever is rife. Immediately a patient is stricken with typhus, the medical officer must call for wine, brandy, beef-tea, and the like, to the consternation of the Board of Guardians; and after all this there will probably come at last the expense of burial. So that every case of typhus is a drain on the parish funds far greater than would have been made by supplying the extra food necessary to prevent it. If, then, the spread of typhus is to be checked, instead of encouraged - if it is to be rendered less fatal when it occurs, instead of more fatal - rations containing the proper elements of nutrition in their proper proportions and quantities must be secured to every member of a family in which one individual is affected with typhus, and also to all those persons who are associated with the infected household.

There is considerable difficulty in selecting diets for the very poor, which combine cheapness and simplicity with the essential chemical composition and a form which the stomach will tolerate. But the two following will be found to fulfil all these conditions, so far as it is possible to do so without the introduction of meat; and in one of them bread is given in the largest quantity consistent with health: -

1. Allowance for twenty-four hours: Bread, 25 oz.; cheese, 2 oz.; butter, suet, or dripping, 2 oz. These yield to analysis: Plastic material, 3.1 oz.; fat, 2.3 oz.; saccharine material, 11.4 oz.

2. Allowance for twenty-four hours: Oatmeal, 16 oz.; milk, 1/2 pint; butter, suet, or dripping, 1 oz. These yield to analysis: Plastic material, 3.0 oz.; fat, 2.3 oz.; saccharine, 9.0 oz.

To each of these diets must be added lime-juice or some land vegetable, salt, and a free supply of pure water.