town populations, has of late years become lowered, there are good grounds for believing that the deterioration has reached its culminating point. Already the results of sanitary improvements in many of our large towns are beginning to declare themselves, not only in a lessened sick-rate and death-rate, but in an apparently healthier tone of public opinion. The working classes in all parts of the country are bestirring themselves for more leisure and more pay, and so far they have succeeded. It remains to be seen whether the leisure will be spent in self-improvement, or the extra pay be judiciously applied, and not worse than wasted. Savings' banks, Good-Templarism, the present diminution of pauperism and crime, are all of them hopeful signs; but it must not be forgotten that holidays and high wages may prove to be a curse instead of a blessing, if they are spent in lawless drinking bouts, and not according to the precepts of health and morality.

SECTION III.-PREVENTABLE DISEASE.

The remarks in the preceding section, fragmentary though they be, suffice to show that, apart from the mortality and sickness arising from material causes, such as impure air, impure water, or insufficient food, there is a vast amount of preventable disease attributable to social causes, which legislative measures, or ordinary sanitary precautions, do not reach. So far as these causes are concerned, the hopes of progress and improvement, as already stated, must rest on education wide-spread and general. The fundamental principles of personal and domestic hygiene must become matters of intelligent conviction amongst all classes, and espe

cially amongst the upper and middle, that they may help those of the lower who are unable to help themselves. For it cannot be denied that there are multitudes in all our large towns so heavily burdened with the load of a vitiated heritage, and so hemmed in with the barriers of foul air, filth, and want, that teaching and preaching can only be felt as bitter mockeries unless these barriers are first removed. Herein lie the duties of sanitary authorities, and in their compulsion by legislative means there is at last some hope that amelioration and enlightenment may penetrate even to these depths.

But limiting the estimate of preventable disease to the operation of causes removable by ordinary sanitary administration, the waste of life is still as needless as it is appalling. This, however, is a tale of culpable neglect, which requires no comment, and is best told in the words of the medical officer of the Local Government Board:- "It seems certain," writes Mr. Simon in 1871, "that the deaths which occur in this country are fully a third more numerous than they would be if our existing knowledge of the chief causes of disease were reasonably well applied throughout the country; that of deaths, which in this sense may be called preventable, the average yearly number in England and Wales is about 120,000; and that of the 120,000 cases of preventable suffering which thus in every year attain their final place in the death-register, each unit represents a larger or smaller group of other cases in which preventable disease, not ending in death, though often of far-reaching ill effects on life, has been suffered. And while these vast quantities of needless animal suffering, if regarded merely as such, would be matter

for indignant human protest, it further has to be remembered, as of legislative concern, that the physical strength of a people is an essential and main factor of national prosperity; that disease, so far as it affects the workers of the population, is in direct antagonism to industry; and that disease which affects the growing and reproductive parts of a population must also in part be regarded as tending to deterioration of the

race.

"Then there is the fact that this terrible continuing tax on human life and welfare falls with immense overproportion upon the most helpless classes of the community; upon the poor, the ignorant, the subordinate, the immature; upon classes which, in great part through want of knowledge, and in great part because of their dependent position, cannot effectually remonstrate for themselves against the miseries thus brought upon them, and have in this circumstance the strongest of all claims on a legislature which can justly measure, and can abate, their sufferings.

"There are also some indirect relations of the subject which seem to me scarcely less important than the direct. For where that grievous excess of physical suffering is bred, large parts of the same soil yield, side by side with it, equal evils of another kind, so that in some of the largest regions of insanitary influence, civilisation and morals suffer almost equally with health. At the present time, when popular education (which indeed in itself would be some security for better physical conditions of human life) has its importance fully recognised by the legislature, it may be opportune to remember that, throughout the large area to which these observations apply, education is little

likely to penetrate, unless with amended sanitary law, nor human life to be morally raised while physically it is so degraded and squandered." (See Thirteenth Report of the Medical Officer of the Privy Council.)

At last the legislature has conferred the power of removing these evils on sanitary authorities throughout the country. The trust is one of life or death to thousands, it remains to be seen how faithfully it will be fulfilled.

CHAPTER II.-FOOD.

SECTION I.-FUNCTIONS AND CONSTITUENTS OF FOOD.

WITHOUT entering into a discussion of the various chemico-physical changes which food undergoes in the living body, it may be broadly asserted that its ultimate destiny is the development of heat and other modes of motion, which together constitute the physiological phenomena of animal life. The potential energy with which the food is stored becomes converted into actual or dynamic energy, and is manifested in the body as heat, constructive power, nervo-muscular action, mechanical motion, and the like. But as food also supplies the materials which are requisite for the development and maintenance of the living fabric, as well as for the display of its various kinds of active energy, it may be inferred that inorganic and organic substances are both necessary. The organic alone are oxidisable, or capable of generating force, while the inorganic, though not oxidisable, are essential to the metamorphosis of organic matter which takes place in the animal economy.

The organic constituents of food are generally divided into nitrogenous, fatty, and saccharine compounds; and the inorganic into water and saline matters. Both classes of constituents are present in all ordinary articles