evils we have found. The means by which total extermination of the disease can be accomplished do not seem to be in sight. So long as there remain cases of consumption in the human family, there remains the possibility of occasional re-infection of bovines. But the probabilities of infection from this source are remote, and should not be taken as arguments against any restrictive measures that might be adopted.

While absolute extermination of the disease at once may not be practical, we believe it to be entirely feasible to so far restrict its dangers as to render them of slight consequence. The State has already, with small expense, eradicated the disease in a considerable number of dairy herds. And what is of more value to the public at large than freeing these herds from disease, it has demonstrated the possibility and the practicability of the plan, and has done much to educate the people as to the sources of danger. The result is that many owners of herds have voluntarily, and at their own expense, had the tuberculin test applied, and the diseased animals destroyed. The work the State has done, is in this way being supplemented; and the practice of testing dairy cows is likely to have a very large increase in the future, without the aid of compulsory measures. Once the herd is free from disease, it can readily be kept in this condition by exercising due precaution in the introduction of fresh stock. Dairymen who have

had unfortunate experience with the disease, have adopted the practice of admitting none but tested cows to their purified herds. This practice, if uniformly adopted, would very soon render the dairy herds of Iowa free from tuberculosis. If in addition to these precautions, similar vigilance were exercised over the introduction of breeding stock to the herds, the chief sources of infection could thus be shut off. If restrictive measures of this kind were applied to these two classes of cattle, practically all the cases of tuberculosis in the State would soon be found, and its ravages reduced to the minimum. The measures adopted in a few score of dairy herds in the State, if applied to the remainder, would go very far toward eradication. It is possible to reach most important practical results without the expenditure of large sums of money or the sacrifice of important interests.

All animals suffering from the disease in any of its stages should be at once removed from contact with other cattle. It is our judgment that any plan which contemplates keeping

tuberculous animals on the farm, and attempting to avert danger by seggregation and other like precautionary methods, will defeat its own ends. The less the number of possible sources of infection in the country, the more successful will be the efforts at eradication. Buildings where tuberculous animals have been confined are to be regarded as infected, and no healthy animal should be assigned quarters in such enclosure till thoroughly disinfected.

It is true, a single test may not in every instance free the entire herd. After-infection may take place. It would be wise in those cases where a number of badly affected animals have existed, to take the precaution of applying additional tests some months after the first. All this involves care, the expenditure of a certain amount of money, and the occasional loss of an animal. But the animal already suffering from an infectious and highly fatal disease can not be considered to possess any high value. The inconvenience and expense attending such precautions are small in comparison with the loss and risk involved in allowing the disease to run its natural course in the herd, and the sale of dangerous products for human consumption.

In most cases the amount of tuberculin used has been two c. c. for animals of one thousand pounds weight. This dose has proven satisfactory, and as we believe it of decided advantage to detect every case of tuberculosis in the herd, if possible, we do not believe the use of the minute dose recommended by some, and which it is claimed may not reveal the mild cases, is advisable. Our experience with that of others goes to show that for each subsequent injection the dose should be increased above the preceding one in order to obtain a satisfactory reaction. If considerable time elapses between the injections, a reaction is more apt to follow. As a rule the first injection produces the most satisfactory results.

The normal temperature of different animals varies much and that the temperature of the same animal may vary considerably at different periods of the day. In some herds the evening (eight, nine or ten o'clock) temperature has been the maximum one secured, while in other herds the morning (eight or nine o'clock) temperature has been the highest. Our observation has been that in Summer the normal maximum temperature is reached in the evening and in the cold weather of Winter in the early forenoon.

The question of normal temperature, as has already been stated, must be carefully considered, as many things beside the injection of tuberculin may cause quite a marked change. We have not found the period of oestrum to alter, to any considerable extent, the regular temperature. In our opinion, when the animal shows an even normal temperature it can be satisfactorily tested, whether in heat, far advanced in pregnancy, or has recently calved.

When the injection is made about ten P. M.-the most convenient time, as the night work is reduced to the minimum— the eight A. M. temperature the next morning will show, in a small per cent of affected animals, a considerable rise above the normal. In a majority of cases no rise will be observed at this time. As those showing a rise reach the maximum at a later hour, there is no necessity of taking the first reading of the temperature until ten hours after injecting, unless the entire upward curve of the fever caused by the tuberculin is desired. While in a great majority of the cases the rise begins before the thirteenth hour, in rare cases the reaction is much delayed and may escape observation unless the temperature be observed, until the eighteenth or twentieth hour after injecting.

The rise, or fever, continues for several hours, reaching the maximum in a majority of cases in from fifteen to eighteen hours, after which it gradually returns to normal. Consequently, a characteristic reaction is one in which the temperature gradually rises above the normal and then gradually recedes back to normal. The degree of the rise, or reaction as it is usually termed, varies somewhat in different individuals, as has been previously stated. A majority of tuberculous animals show a maximum above one hundred and five. A few only have a temperature above one hundred and seven. The animal slightly diseased, as a rule, shows a higher temperature than one having the disease in a severe form. One investigator has stated that a temperature of one hundred and seven or above indicated that the lesions in that animal are microscopic. Such has not been our experience.

As to what should be considered a reaction is a very important question. All workers unite in saying that a rise of two degrees or over indicates tuberculosis, and probably all would say that a less rise may and does in many cases indicate the disease. Our experience and that of many others goes to show that a rise of one and a half degrees is sufficient to condemn

the animal as tuberculous. In some cases it is very probable that a rise of even one degree continuing for four or five hours and occurring when the reaction should occur, indicates lesions in some part of the body. We have found, as have also others, that an animal badly diseased does not as a rule react strongly, but that a physical examination of these will reveal the disease in most instances, without which it may be overlooked.

The effect of repeated injections has been considered with a view of determining whether by making a second test a doubtful record could be cleared up, the animal proven healthy or diseased, and whether by the use of several injections a diseased animal could be cured. In some cases the reaction after the second injection was less than after the first and no appreciable rise followed the third test. In these animals the amount of tuberculin used in the second test was greater than in the first, and our experience as well as that of others, indicates that in order to secure as great a rise after the second injection as that following the first, the dose of tuberculin should be increased. With a considerable increase in dose and the elapse of several weeks between tests, we believe satisfactory results can usually be obtained by testing the doubtful cases twice.

Two of

Autopsies were held on three of the diseased animals that had received at intervals ten injections of tuberculin. these were fat, apparently in the best of health, and showed only very slight lesions. It seems very probable that in these animals the tuberculin exerted, to a certain extent at least, a curative effect. More observations will have to be made along this line before anything definite can be stated.

In our autopsies a bronchial lymph gland was involved in a majority of the cases. In a number of instances this gland was much enlarged, containing a number of tubercles, in different stages of degeneration, when lesions were observed in no other region. It is a noteworthy fact that in a majority of the animals found diseased and destroyed, the disease had been chronic and the lesions very limited. Nevertheless the large number of diseased animals in herds where acute cases are absent indicates that the mild case is always a source of danger.