INFECTIVE GRANULO.MATA. 35,T 



of time. The glycerine bouillon culture is filtered and the fil- 

 trate sterilized by heat and concentrated to the desired strength 

 by evaporation over a water-bath. The active princii)le of tuber- 

 culin is probably a nucleo-proteid or its cheniic derivati\'es. 



Tuberculin is a vers- reliable diagnostic agent. Its chief use 

 in veterinary medicine has been in the diagnosis of tuberculosis 

 in cattle. It is practically as reliable in the detection of human, 

 ptircine and probabh- a\-ian tulierculosis as in the detection of 

 bo\-ine tuberculosis. The principal method of ap])lication has 

 been liy subcutanenus injections and noting the temperature 

 changes in the suspected animal. The normal temperature of the 

 animal is ascertained pre\ious to the injection and the tempera- 

 ture is taken e\"ery twi-i hours, beginning eight hours after tubcr- 

 culinatir)n. ( )n the da\- succeeding the injection a rise of from two 

 to three degrees Fahrenheit is considered a reaction and tliis sig- 

 nifies that the patient is tul;>erculous. This rcactirm is ]irijbal)ly 

 due to the specific irritating action of tlie injected tnl)erculin 

 ujion the tul)ercnlar foci producing intense hy]iercmia ai'ound 

 and disintegration of the tuliercle. Thus there is a sudden dis- 

 charge of tubercular products into (he s_\-stem and the intense re- 

 action, thermic and constitution.al follows. 



.\ purified tuberculin used directh- in the c injunctival sac 

 is now iiu the luarkct. Tlie ophthalmic reaction consists of llie 

 production of a marked h_\-])eremia of the conjunctix'e in from 

 six to ten hours after tuljerculination. At the present time 

 the technic|ue is at fault or the lu1)ercidin is of inferior (piality 

 and the ophthalmic tulierculin test cannot lie relied upon. 



ACTINOAIYCOSIS. 



Actinomycosis is a specific, inflanuuatory granuloma, caused 

 by the Cladothri.x actinomyces and characterized by the forma- 

 tion of tumorous masses of fibrous tissue that usually develop 

 suppurating centers and fistulous tracts. 



Distribution and extent. — Actinomycosis is prevalent m fui- 

 rope, Australia, Africa. North and South America. The extent 

 of the disease varies in different countries. According to the •.' Ith 

 Annual Report of the Bureau of Animal Industry there were 

 slaughtered in establishments having federal inspection 7,621,717 

 cattfe, of which 22,742 were found to be affected with actinomy- 

 cosis,' or one in about each 340. The actual per cent is even 

 larger, for many animals afflicted with actinomycosis are slaugh- 

 tered where there is no^official inspection maintamed. 



Susceptible Animals.— Cattle are more frequently affected 



