BAOTEEIA AND THEIR ALLIES 169 



With the view of throwing light upon this important question, 

 by the production of actual evidence, I obtained a sheep's kidney 

 from a recently killed animal, and saw a coating of fat nearly an 

 inch thick stripped from it. The whole organ was then left to 

 soak for four hours in a two per cent, solution of chromic acid, 

 so as to destroy any organisms by which its surface may have 

 been contaminated. It was then removed and placed in a bottle 

 still wet with another germicidal solution, namely, a ten per cent, 

 solution of formalin. The screw-top having been fixed so as to 

 prevent evaporation, the bottle was transferred to an incubator 

 and left at a temperature of 76° F. for thirty-six hours.' When 

 the organ was cut the chromic acid solution was found to have 

 discoloured it to a depth of about a quarter of an inch, but within 

 that margin the kidney substance was red and only slightly softer 

 than natural. There was no distinct odour of putrefaction. A 

 small portion of the organ was cut out and teazed in a drop of 

 a weak solution of gentian violet, and fragments, after a short 

 interval, were carefully examined under the microscope. A com- 

 paratively small number of Bacteria were found free, between 

 the separated and broken-up cells, and the cells were densely 

 filled with granular matter, as may be seen in Fig. 2, A ( x 700), 

 but it was impossible to identify with certainty any of the granules 

 as germs of Bacteria. Sections that were made and carefully 

 stained gave no more definite results. 



Another sheep's kidney from a freshly killed animal was there- 

 fore obtained and treated in the same manner except that it was 

 left in the incubator at 76° F. for three and a half days, instead 

 of merely thirty-six hours. When the organ was cut through it 

 was deeply stained at the circumference, as before, with the chromic 

 acid ; but the red tissue within was much softer, and the odour 

 was most offensive and putrid. Portions of the organ were at once 

 put into a ten per cent, formalin solution with a view to obtaining 

 sections therefrom ; but a minute portion was cut off, as before, 

 and teazed in a drop of gentian violet. On examination with the 

 microscope, after a brief interval, I found the fragments of the 

 tubules and kidney cells full of Micrococci which had taken the 

 stain well, together with numbers of figure-of-eight organisms 

 and short chains (Streptococci) such as are shown in Fig. 2, B 

 (X 700). 



' I was using the incubator for other purposes at this temperature, and there- 

 fore did not make use of a higher temperature. 



