THE LUNG PLAGUE OF CATTLE. 27 



this with a positive disproof. In Europe, the bleak and stormy mount- 

 ains of Scandinavian! the latitude of (irccnland, and the Scottish High- 

 lands in the latitude of Labrador, have maintained a permanent immu- 

 nity, while the plague was remorselessly ravaging the. sunny fields of 

 England, France, and Italy. In America the plague lias prevailed, for 

 thirty -three years on the genial sea-coast of the Middle States, while it 

 has spared the whole interior of the continent, where the temperature 

 descends so much lower. Nor is it the raw sea-winds that generate it, 

 since from Connecticut north to Labrador no such disease has ever ap- 

 peared apart from its one importation into Massachusetts. 



HIGH TEMPERATURE HAS NOT GENERATED LUNG PLAGUE. 



It is worthy of note that the European countries ravaged by this plague 

 have been especially those of Central Europe, where the greatest traffic 

 in cattle and the most extensive wars have ever taken place, white Spain, 

 Portugal, and the Channel Islands, which have no such traffic with the 

 rest of Europe, have throughout escaped infection. The same immunity 

 has been preserved in the whole of Africa (excepting its southern ex- 

 tremity, since the importation of the Dutch bull) ; in other words, through 

 the whole tropical part of the continent in all of our Southern States, 

 in .Mexico, in the West Indian Islands, and in the whole of Central and 

 South America. However much the disease may be aggravated by a 

 hot climate, as witnessed in South Africa and Australia, and in our own 

 semi-tropical summers, there is not a shadow of support for the idea 

 that it is generated by a high temperature. 



LUNG PLAGUE NOT GENERATED BY A TEMPERATE CLIMATE. 



In this connection, we need only instance the cases of Spain and Port- 

 ugal, of the Channel Islands, of Canada, of our own Western States, of 

 the Pacific States, and of the great stock-raising plains of the La Plata, 

 also of the British Isles before 1840, of South Africa before 1854, of 

 South Australia and Tasmania before 1859, and of New Zealand before 

 1864. We may also adduce such States, as Massachusetts and Con- 

 necticut, Norway, Sweden, Denmark, Schleswig-Holstein, Oldenburg, 

 Wurtemberg, and Switzerland, as have stamped out the imported dis- 

 ease, and preserved sound herds until in some cases reinfected by the 

 occurrence of a new importation. 



LI'NG PLAGUE NOT GENERATED DE NOVO BY THE PRIVATIONS OF 



TRAVEL. 



We have already seen that until the great advances of agriculture 

 and commerce in the present century the lung plague was mainly propa- 

 gated by the wars of Central Europe. But that the mere privations of 

 cattle in the army herds did not generate the poison de novo is shown 

 by the hannlessuess of the frequent wars of Sweden in the eighteenth 

 century and early part of the nineteenth ; by the continued immunity of 

 Spain throughout her desperate wars of the seventeenth, eighteenth, 

 and nineteenth centuries ; by the absence of the plague during and alter 

 the wars of independence of the South American republics ; by the same 

 absence of any such disease during and after the war of independence 

 of the United States ; during the war in Texas in 1836 ; during the wars 

 in Mexico in 1845 to 1848 and 1861 to 1867 ; and, finally, during our civil 

 war, 1861 to 1865. In reference to these North American wars it should 



