Pleuro- Pneumonia of Cattle. 205* 



Lungenseuche Mit Hilfe Der Kemplementablenkung," by Titze 

 and Gieze, published in the Berliner Tierarztliche Wochenschrift r 

 No. 32, Vol. 35 (August, 1919, pp. 281-282). Unfortunately, I 

 have not been able to see the original article by Titze and Gieze,. 

 but it would appear from the abstract already referred to that, 

 while there are many points in common in regard to the re- 

 action described by Titze and Gieze, and that which I have just 

 described, they differ in certain very material points. Titze and 

 Gieze used as antigen tissue the fresh lung and bronchial lymph 

 glands taken from an infected animal. With this tissue they 

 prepared : — 



(1) A watery extract by boiling, afterwards centrifuging to- 

 obtain a clear solution, which was then made isotonic by the 

 addition of the necessary quantity of sodium chloride. 



(2) An alcoholic extract which was afterwards cleared in. 

 the centrifuge, and diluted with from 10 to 50 parts of saline 

 solution. Since reading the abstract of Tietze and Gieze's work 

 I have prepared, and tried alcoholic extracts of diseased lung. 

 While it is possible to obtain complement fixation with such ex- 

 tracts, the results obtained with them have not been satisfactory,, 

 and in certain instances have been quite unreliable. I am thor- 

 oughly of the opinion that sub-epidermal tumour tissue is better 

 material from which to prepare the antigen. Alcoholic extract 

 of dried sub-epidermal tumour tissue gives uniform fixation, and 

 thoroughly reliable results, if the technique laid down is care- 

 fully followed. 



It is probable that an alcoholic extract prepared from fresh 

 subepidermal tumour tissue will give equal, if not better, results 

 than that prepared from dried tissue, but, at the present time,. 

 I have not had an opportunity of testing it. 



Titze and Gieze mention the haemolysis which often occurs, 

 after a positive result, and quite correctly refer to the necessity 

 of carefully titrating the complement, in order to ascertain the 

 absolute M.H.D. In the method of complement titration we 

 differ in technique, but either method gives good results. While 

 mention is made of the fact that haemolysis usually follows a 

 positive result, Titze and Gieze apparently do not attempt to ex- 

 plain the phenomena which bring about that haemolysis. 



The tests which I have conducted, in order to determine the 

 influence of conglutinin on haemolysis in the complement fixa- 

 tion test in contagious pleuro-pneumonia, offer an obvious ex- 

 planation for its occurrence. It seems quite evident that the: 



