194 



On the Possibility of Determining the Presence or Absence of 

 Tubercular Infection by the Examination of a Patient's Blood 

 and Tissue Fluids. 



By A. E. Wright, M.D., sometime Professor of Pathology, Army Medical 

 School, Netley ; Pathologist to St. Mary's Hospital, London, W. ; and 

 Staff-Surgeon S. T. Eeid, K.N. 



(From the Pathological Laboratory, St Mary's Hospital, London, W.) 



(Communicated by Sir John Burdon Sanderson, Bart., F.R.S. Received 

 October 21,— Bead November 23, 1905.) 



In the present communication we propose (a) to set forth certain con- 

 clusions arrived at after the study of the tuberculo-opsonic power of the blood 

 in a very considerable number of tubercular patients ; (b) to show that we 

 have in the measurement of the tuberculo-opsonic power of the blood and 

 tissue fluids a method which may be exploited in the diagnosis of tubercular 

 infection. 



Technique Employed. — The technique employed by us in the measurement 

 of the tuberculo-opsonic power of the blood was essentially that described by 

 one of us in conjunction with Douglas.* In each case the white corpuscles 

 required for the tests were derived from blood from the finger received into a 

 solution of 05 per cent, citrate of soda in 085 NaCl, and rewashed after 

 centrifugalisation in a considerable volume of - 85 NaCl, and then again 

 centrif ugalised. Of the " blood-cream," obtained by skimming off the upper 

 layer of the corpuscular sediment, one portion was in each case mixed in a 

 capillary tube with one volume of serum and one volume of a suspension of 

 tubercle bacilli which had been centrifugalised in such a manner as to free it 

 from bacillary clumps. After incubation at 37° for 15 to 20 minutes films 

 were made on slides prepared with emery paper.f These films were, after 

 fixture in saturated corrosive sublimate, stained with boiling carbol-fuchsin, 

 decolourised with 2 per cent, sulphuric acid, and counter-stained with 

 methylene blue after washing in 1 in 1000 sodium carbonate. The standard 

 of comparison employed was obtained by mixing in each case the same 

 " blood cream " and tubercle suspension with " pooled normal serum.":}: 



* ' Koy. Soc. Proc.,' vol. 72. 



t "Wright, ' Lancet,' July 9, 1904. 



\ "While in this research pooled serum was employed, in order to provide against any 

 chance variation of our bloods under the physical strain entailed by the work, it is to be 

 noted that the observations of TJrwick, conducted in this laboratory, and the more exten- 



