From 1775 to 1791, seventeen years, the mortality among the cavalry was 181, and among the infantry 349, out of 10,000 living; but in the ten years from 1834 to 1843 these rates were only 108 and 215.[9] Colored troops are employed by the British Government in all their colonies and possessions in tropical climates. The mortality of these soldiers is known, and also that of the colored male civilians in the East Indies and in the West-India Islands and South-American Provinces. In four of these, the rate of mortality is higher among the male slaves than among the colored soldiers; but in all the others, this rate is higher in the army. In all the West-Indian and South-American possessions of Great Britain, the average rate of deaths is 25 per cent, greater among the black troops than among the black males of all ages on the plantations and in the towns. The soldiers are of the healthier ages, 20 to 40, but the civilians include both the young and the old: if these could be excluded, and the comparison made between soldiers and laborers of the same ages, the difference in favor of civil pursuits would appear much greater. Throughout the world, where the armies of Great Britain are stationed or serve, the death-rate is greater among the troops than among civilians of the same races and ages, except among the colored troops in Tobago, Montserrat, Antigua, and Granada in America, and among the Sepoys in the East Indies.[10] In the army of the United States, during the period from 1840 to 1854, not including the two years of the Mexican War, there was an average of 9,278 men, or an aggregate of 120,622 years of service, equal to so many men serving one year. Among these and during this period, there were 342,107 cases of sickness reported by the surgeons, and 3,416 deaths from disease, showing a rate of mortality of 2.83 per cent., or two and a half times as great as that among the males of Massachusetts of the army-ages, and three times as great as that in England and Wales. The attacks of sickness average almost three for each man in each year. This is manifestly more than that which falls upon men of these ages at home.[11] SICKNESS AND MORTALITY OF THE ARMY IN WAR.