not. Of the 679 not vaccinated 274 (40.8 per cent) died; of the 487 vaccinated 3 (less than I per cent) died. During the Franco-Prussian War the Germans practicing vaccination had 4,835 cases and 276 deaths; while the French army in which vaccination was neglected had 125,000 cases and 23,470 deaths. The French army, though much smaller than the German, had 26 times as many cases and 86 times as many deaths. In the World War there was not a case in the French army up to the end of 1917. Later there were 4 cases and no deaths. The British army had 12 cases and 3 deaths. The American army 979 cases, of which 241 were infected on enlistment, and 15 deaths. When the United States took over the Philippines there were about 6,000 cases yearly at Manila. Compulsory vaccination was introduced and there was not a case for seven years. Under the Harrison régime, vaccination was neglected and a marked increase in smallpox was evident by 1918. By 1921 there had been 130,264 cases and 74,369 deaths. General Wood reintroduced compulsory vaccination in 1921 and the plague was stopped by 1923. Meantime among 5,442 American soldiers in the islands there had been but 7 cases and one death. In 1920, New York, New Jersey, Connecticut and Maryland had 688 deaths while Washington and California had 9,137; that is, two western states with one-fourth the population of the eastern states had thirteen times as many deaths. The explanation is to be found in the repeal by California of the compulsory school vaccination law in 1911 followed by the repeal of all vaccination laws in 1921. California had 26,651 cases between 19191924 while Massachusetts had only 126. Washington repealed its vaccination law in 1919 and in 1920 had seven times as many cases as in 1917. In the epidemic at Detroit in 1924 there were no deaths among those successfully vaccinated within five years; 7 among those successfully vaccinated over seven years and 123 among the unvaccinated. Our Public Health Service reported in 1925 that smallpox had 5 increased 75 per cent since 1923 and the deaths had increased 28 per cent. This estimate was for the world. India had the most cases but the United States had 55,538 cases in 19231924, about one-fifth of the world's total. We can hardly congratulate ourselves on our superior intelligence when we allow a few sincere but evidently mistaken enthusiasts to destroy our protection against one of the worst of diseases. One of our most distinguished surgeons, W. W. Keen, of Philadelphia, is the authority for the statements just made. The story is the same all over the earth. From 1893 to 1897 smallpox caused the deaths of 275,502 persons in Russia as against 274 in Germany where vaccination was compulsory. During this period Spain lost 563 per million inhabitants, Russia 463, Germany only one, and Germany has had no epidemic since 1874. In Philadelphia between 1901 and 1905 some 500 persons died of smallpox, not one of whom had been successfully vaccinated within ten years. The epidemic of 1891-1892 cost Philadelphia over $21,000,000 while the total cost of vaccination, disinfecting stations, public instruction at the same time was some $750,000. No one claims that vaccination is as pleasant as eating a dish of ice cream but the danger is not much greater. Schamberg claims that in 6,739,902 cases of vaccination there were only 476 deaths later which by any stretch of imagination might be attributed thereto, a rate of 0.007. Keen says that the records show 25,500,000 vaccinations without subsequent deaths due thereto and reports only 45 cases of lockjaw in millions of vaccinations. It happens that the writer spent some months in Haiti during a great epidemic in 1921 and had plenty of opportunity to see the situation at first hand. To see the victims sick along the roadsides, or dying in lonely cabins by the hundred; to learn that the ignorant peasants were copying the old method of vaccinating themselves from light cases, was enough to convince him that Jenner was one of the benefactors of men. Here, then, man has control, unless he stupidly refuses to learn from experience and reverts to the practice of Colonial times in America. Milk, being white, cured "bladder humor," and when mixed with saffron and a bit of salt could be prescribed as a cure for jaundice, for since jaundice is a yellow disease, only a yellow remedy could be effective. In New York City, apparently, the dosing had more variety, and certainly required greater ingenuity in its performance, such as catching twenty head lice and mixing them with nutmeg, sugar and a little turmerick. In cases of poisoning a black powder was the cure, and as toads were considered poisonous they were used in its compounding. Moss taken from skulls of the dead and applied to a weapon with which a wound had been inflicted, and the weapon in turn laid in the abrasion, would result in a cure. Bedbugs for obstetrical cases, and the flesh of boiled mice for timidity are but a few of the obnoxious and loathsome remedies listed in Barrough's "Method of Phesecke," and "Green's Medicine." It should not be forgotten that smallpox is kept alive because somewhere, all the time, some one has it. It may be in such mild form that it is not recognized but as it is passed along it may develop a more virulent type to become an epidemic when it reaches an unvaccinated group. A generation which has not seen smallpox is likely to become careless about vaccination. Note well that here is a case where man turns his enemy against itself and that he is unable to make any direct frontal attack on the disease. Yellow Fever Yellow fever offers a most interesting contrast. This fever appears to have been native to the warm shores of the Caribbean from Yucatan to Brazil and to have been carried to the western coast of Africa immediately after the discovery of America though there is a possibility that the slave ships brought it from Africa. It has never reached the Orient. It was taken by sailing ships to Havana in 1762 and was endemic thereafter. It has reached the United States a number of times, as in 1793 when 4,041 of the 40,144 inhabitants of Philadelphia died of it between August and the middle of September. The greatest epidemic was in 1878 in the southern states whose cost was at least $100,000,000 in money and thousands of lives. Yellow fever kills about 25 per cent of the adults attacked and is usually a very severe disease, but some children and adults have very light cases. In an endemic center probably every person is attacked at some time during life and the seeming immunity of the native population as compared to immigrants is due to these light cases. The cause of the disease remained a mystery during the nineteenth century and the manner in which it reached human beings was equally unknown. It had been noted by Rush of Philadelphia that mosquitoes were very prevalent during the epidemic. A number of later observers suspected that the mosquito had something to do with its transmission and this belief grew after Manson proved in 1879 that the nematode causing filariasis (elephantiasis) utilized the mosquito as an intermediate host. By this time Finlay of Havana was convinced that the mosquito was responsible but he was unable to prove it. During the Spanish American War the American troops were rendered almost useless by disease, including yellow fever, and the medical board started a careful investigation. General Gorgas became health officer in Havana and cleaned up the city but the disease persisted. Then came the epochmaking survey in 1900 by Reed, Carroll and Lazear in which the last lost his life from the disease. They were able to prove that it was not transmitted by contact with the sick nor with dirty clothing but was transmitted by a common species of mosquito (Stegomyia) which breeds near human habitations. To-day the history is clear. Yellow fever is produced by an animal parasite which is introduced into the human body by the mosquito. If the patient is bitten in the early days of the disease by another mosquito the germs are transferred to the mosquito and after a period of about twelve days may be again transferred to man. The direct inoculation of a healthy person with blood from a patient will produce the disease but in actual life this is not likely to happen. This discovery at once changed the entire procedure. All that need be done is to keep a patient in mosquito-proof quarters and the disease will not spread. FIG. 4. MORTALITY FROM YELLOW FEVER IN HAVANA Monthly average for 20 years preceding 1900. Lower dotted line shows 1901 mortality. In this case a frontal attack is possible. By protecting the patients against the mosquitoes the spread of the disease is checked and by the destruction of breeding grounds the disease may be eliminated. The history at Havana is enlightening. During the nineteenth century the deaths from yellow fever at Havana had frequently been as high as 1,500 per annum, a rate of 428 per hundred thousand population, but they |