EXPERIMENT STATION BULLETINS. 523 



of the aninial to which the test is to be applied shall be taken every two 

 hoursduriugthedayprevioustothe injection of the fluid. About ten o'clock 

 at night the fluid is introduced beneath the skin of the animal — about 

 a half teaspoonful of the fluid which has previously been diluted for 

 convenience in handling. It is customary to administer about half the 

 dose to yearlings and two-year-olds, while very large cows and male 

 animals received about a teaspoonful. It has been my custom to leave the 

 animals to themselves after injecting for about eight hours, when the 

 temperature is again taken, and observations of the heat of the animal's 

 body should be made every hour during the day after the tuberculin has 

 been administered. My observation has been that those animals which 

 are affected with the disease begin to react about nine or ten hours 

 after the medicine has been given and continue to do so for about four or 

 five hours when the temperature will begin to fall and soon reach the 

 normal. There is, however, considerable variation in individuals in their 

 behavior as to the time and degree of reaction towards the medicine. It 

 is customary to regard an animal as affected with the disease when 

 it shows a temperature two degrees above the highest point of the day 

 previous to the administration of the medicine. In cases where the re- 

 action is less than two degrees it has been my practice, where I have had 

 full control of the herd, to place such animal in the doubtful list to be 

 retested at a future time." 



• 



Since Professor Grange has been connected with this work of the sta- 

 tion, I wish to quote him further in regard to his idea of the interpretation 

 of the tuberculin test. There is ample room for different interpretations 

 and I desire that his reports shall fairly represent his views. His interest 

 in this work has remained unabated. 



"A brief account of some animals which were placed in the doubtful 

 list, will, no doubt, impress the reader with the very great importance 

 of careful manipulation of the thermometer in reading it, and also im- 

 press upon him the advisability of retesting animals which have shown 

 the slightest indication towards a rise in temperature the day after the 

 fluid has been given. 



"On the 31st of March, 1896, I tested a herd of 67 cattle. Among them 

 nine animals reacted in a manner indicating tuberculosis, while 18 of 

 them dropped into the doubtful list, one of which only reacted one-tenth 

 of one degree, another three-tenths of a degree, another six-tenths of a 

 degree, and still another one degree and eight-tenths. On the 11th of May 

 these animals were retested. The first one reacted two degrees and six- 

 tenths, the second one, six-tenths of a degree, the third one, one degree 

 and five-tenths, the fourth, two degrees. The first and fourth w r ere con- 

 demned according to the requirements of the test. The fourth animal 

 was badly affected with the disease which was very apparent upon the 

 most casual observation. The first one, or No. 1, although reacting two 

 degrees and six-tenths did not show any external manifestations of the 

 disease but was killed and after a diligent search some of the cheesy 

 tubercle was discovered. Not being satisfied with the ocular examination, 

 the microscope was used when the bacillus was discovered. Besides 

 this, some of the material was inserted beneath the skin of a Guinea pig 

 which eventually died of tuberculosis and in this animal the germs could 

 readilv be seen when stained according to Ziehl's method. No. 4 was also 

 killed and showed such exaggerated lesions of tuberculosis that nothing 



