ENTERIC FEVEE PATHOLOGY. 



Under the above heading in Dr. Lewis's journal for 1881 there is the following entry : — 



" During July and August I made numerous attempts to obtain satisfactory life size 

 photographs of enteric-fever intestines, but owing to the uncertainty of the light during 

 the rains at Simla, it was found very uncertain work — it being almost impossible to obtain 

 sufficient density with Wratten and Wainwright's gelatine plates — the pictures were 

 nearly all either over or under exposed. During the last few days, however, the photos 

 obtained were very satisfactory, so I jot down the experience for future guidance. 



" Sept. 5. The sun clouded just to the extent of permitting me to look at it without 

 really blinking. The preparation and table taken out into the open air. The piece of 

 intestine carefully stitched on to a piece of glass, slightly larger than the preparation, and 

 fastened on to a deal board [over which some black velvet has been spread] by means of 

 four shortened black pins. 



" The preparation placed about 6^ inches in front of a No. 1 symmetrical lens 

 (Ross's 3' focus), and the ground glass of camera about 6^" from back glass of lens. The 

 object very carefully focussed by means of a 3" objective mounted in a cardboard tube 

 of suitable length, so as that the focus of the image should be exact when the tube rested 

 on the smooth surface of the ground glass. This accomplished, apply No. 5 stop, which 

 brings the image sharp to the edges of a 5 x 4 plate. Exposure 80 to 90 seconds." 



The plates were developed with pyrogallic acid and ammonia, and generally they 

 were found to require intensification. 



October 1st, 1881. 



Six negatives were selected and despatched to Major Waterhouse, 40, Hamilton 

 Terrace, London, N.W., for reproduction by the Autotype process, or any other he might 

 select. 



Septemh&r 2'6rd, \^S\ . 



