YELLOW FEVER EXPEDITION 
precautions could be taken, yet still the fine small bacillus appeared. Later the plan 
was tried of putting a large number of big loopsful into saline solution with a small 
quantity of corrosive sublimate, and after several good shakings allowing the stuff to 
sediment ; thereby it was hoped that possibly in the lower part of the tube one might 
be able to concentrate the bacilli from a larger quantity of tissue than could be 
examined otherwise. The method is merely an application of the common technique 
in examining doubtful sputa for tubercle bacilli. At the same time ordinary smears 
were made for control. In this way we found the small fine bacillus with greater 
facility than in the plain smears. 
At the earlier stage when examining centrifugalized blood we had sometimes 
examined the bottom of the tubes for bacilli, but without much success ; further 
examinations of early cases were to have been made by allowing slow sedimentation 
to occur whereby time would be allowed for the heavier particles to sink first, which 
is not the case when slightly diluted blood is centrifugalized in a narrow tube. The 
method was tried in rather long tubes with the borax-boracic acid mixture used for 
tubercle, but no early cases were obtainable at the hospital except a man from a 
ship nearly all of whose crew were affected with yellow fever, a disease which 
he had already had some years before ; besides tertian parasites in his blood, the 
sediment yielded a small bacillus similar to that in the yellow fever cases; a control 
case of malaria examined at the same time with the same batch of tubes and medium 
gave negative result. It was certain that he had been exposed to yellow fever infection 
on the ship, and it was possible that these bacilli were the consequence, though the 
course of his temperature corresponded with the ague infection. 
Naturally we turned to Dr. Sternberg's book, to see whether this assiduous 
observer had recorded anything similar to the small bacillus which we found. The 
following may be quoted : 1 'I have had my attention especially attracted by an 
extremely slender and long bacillus which has been very abundant in many of the 
smear preparations, but which has never shewn itself in my cultures (contents of 
alimentary canal). It is the smallest organism so far as its breadth is concerned that I 
have yet encountered ; it is a flexible filament, as shewn by the various shapes it 
assumes, and may reach a length of fifty micromillimetres or more.' This turned 
our attention to the examination of the faeces, and, at our final autopsies, the intestinal 
contents, and we found an extremely fine bacillus, sometimes in extraordinary 
numbers, so that in a whole field of a '/„ O.E. objective there were but few other kinds 
of bacilli ; we did not see such lengths as Sternberg mentions ; its tenuity was such 
that by opening the aperture of the condenser to a point at which the larger ordinary 
faecal bacilli were still visible, the fine one completely disappeared ; in such examina- 
tions of fresh unstained faeces, no motility could be detected. Like the bacillus 
found in the tissues it did not stain with great readiness ; thus, F.G., seventh day, 
I. Sternberg, Report on the etiology and prevention of Yellow Fever, Washington, 1890, p. 113. 
