that, in the two years, 216 births, or 6.5 per cent. of the American births, were a gain to the American class, and 399 births, or 5.7 per cent. of the foreign births, were a gain to the foreign class of the population.

This shows that in Boston, containing more than one-quarter of the whole foreign population of the State, the mortality among the foreign class is as excessive as their fecundity, and it seems probable that an analysis of the original returns from all the towns and cities of the Commonwealth, which can be made for the next annual report, will furnish similar results.

That the foreign population is still gaining upon the native, in Msssachusetts, is exceedingly probable. The process has been going on with greater or less rapidity for a long period, and its causes are to be found in the emigration of natives and the immigration of foreigners. From every town and village, the stream of native emigration has steadily flowed since the beginning of this century; first to Western New York, then to the NorthWestern States and the Mississippi Valley, and, as new fields were opened to thrift and enterprise, to the most distant regions of this continent, and to every part of the world. It may be regarded as remarkable under these circumstances that the native population should increase at all, and it is exceedingly probable that but for the removal of natives of other States, chiefly New England, to our manufacturing and commercial centres, it would not take place. Certain it is, that before foreigners began to come among us in large numbers, the population of many towns was stationary, and in not a few instances retrograded. Between 1820 and 1840, eighty towns lost population. In 1850, Dr. Jesse Chickering writes as follows: "In 159 towns, being more than half the whole number in the State, and containing more than a third of the whole population, there has been an aggregate loss of twentyfour persons in the past ten years, 1840 to 1850; and these same towns gained only 5.06 per cent. in the preceding twenty years." All this shows that a great multitude of natives of Massachusetts have found new homes in other regions; and the transfer of population still goes on.

The following remarks upon the rate of mortality in different countries are from an "Address on Public Health," before an association for the promotion of social science, by Dr. Farr, recently published in England:

"As political economy rests upon the idea of value, so our science rests upon the idea of health, and it is as important to us to find a measure of health as it is to the economist to find a measure of value. That measure must be simple, and applicable to all countries. Now, the measure that is in universal use is the rate of mortality; a unit of life loses a certain fractional part by death every moment, and the amount of loss in a unit of time expresses the rate of mortality. The unit of time is always a year, and the rate of mortality is found by dividing the deaths by the mean numbers living multiplied into the time. The rate varies from 020 to 040 in England; that is, in one place the deaths are 20, in another 40 to 1,000 living. In a normal community, constituted of persons of all ages by an equal number of annual births, there is a fixed mathematical relation between the rate of mortality and the duration of life. Thus, if the average rate of mortality in two cities is two per cent. and four per cent., then the mean duration of the lives of the inhabitants is fifty years in one city, and twenty-five years in the other. Therefore in saying that rate of mortality measures, it is conversely affirmed that length of days measures the health of nations. As the population fluctuates, certain corrections are necessary; the rates of mortality are determined at various ages, and from these the probabilities of living year by year are calculated and set forth in a life table that determines the path every generation passes over from rising to setting. Public health now engages the attention of every civilized State; so we can pass in review the principal populations of Europe, and from the researches of their own statists learn by this measure their comparative health. I take the population in the lowest stage of health first, beginning with Russia. That empire is emerging from barbarism. Their death-rate is 36 per thousand. The death-rate of the new kingdom of Italy, is 30. It is a peculiarity of Italy that the population of the country is as unhealthy as that of the towns. The deathrate of Spain is now 28; of Prussia, 29; of Austria, 30; of Norway, 17; of Sweden and Denmark, 22; of Holland, 26; of Belgium, 22; of France, 22; of Great Britain, 22."

CAUSES OF DEATH.

The weather is important to be noted in connection with the public health.

Through the kindness of the authorities at Harvard, Amherst, and Williams Colleges, we are enabled to give the following table.

MEAN TEMPERATURE of the air, and amount of rain-fall for each month of 1865.

It appears from a table contributed by Robert Treat Paine, Esq., to the Eighteenth Registration Report, 1859, that the aver

age fall of rain and melted snow in Boston for thirty-five years ending with 1859, was 43-29 inches.

The average rain-fall at Greenwich, England, for twelve years, 1848-59, was 23.53 inches.

The hygrometric condition of the atmosphere in the two countries is as follows:

The force of vapor is expressed by the fraction of an inch to which a column of mercury is sustained by the existing vapor.

The humidity is given in hundredths of complete saturation. For the American observations we are indebted to Professor Snell, of Amherst College. The English observations are from the Reports of the Registrar-General of England.

Although fever and dysentery prevailed to an unusual degree in certain localities, there was during the year a happy exemption from marked epidemic influence in several diseases which in many former years have been most destructive to life. The result is that, on the whole, the class of zymotic diseases compares favorably with several previous years. The percentage of this class is 31.20, which is less than in any year since 1862. It is still however 21 per cent. above the average for the last quarter of a century.

The percentage of constitutional diseases is 24.84, which although slightly greater than the two previous years, is about the usual average. It is particularly gratifying to observe that tubercular diseases, including that terrible destroyer of our race, consumption, show a percentage of 20.74 which is 3.36 per cent. less than the average for twenty-four years and eight months, ending with the present year.

The percentage of local diseases is slightly in excess of previous years.

Developmental diseases are in larger percentage than in the two previous years, but do not vary materially from the average of many preceding.

Violent deaths show a marked decrease, attributable to the happy close of the war; falling in one year from 5.76 to 3.53 per cent. Sixty-one are reported "killed in battle," which is 573 less than the previous year.

Eighty-six males and 16 females lost their lives by railroad accidents. Twenty-nine persons, of whom all but one were males, are reported to have died from starvation; probably nearly all of them in rebel prisons. Fifty-seven males and 21 females committed suicide. There were no judicial executions in 1865. Two men are reported killed by lightning, 11 were lost at sea, 9 men and 2 women were the victims of murder, 2 men died from excessive cold, 14 men and 3 women from excessive heat, and 19 persons died from poison.

Among the diseases whose numbers vary greatly from year to year (all of them in the class of zymotics,) dysentery, typhus fever, and hooping cough prevailed more than in previous years, while the ravages of scarlatina, croup, diphtheria and measles were happily very much diminished. A comparison of the mortality from these seven diseases during the past two years will show how greatly they may vary in successive seasons.

The mortality from the ten most destructive diseases in each of the past five years, with the annual average for the whole period, is shown in the following table :