ON THE POSSIBILITY OF INFECTING OYSTERS 

 WITH TYPHOID BACILLI. 



By CYRUS W. FIELD, M.D., 



ASSISTANT BACTERIOLOGIST, DEPARTMENT OF HEALTH, N. Y. 



THIS work was undertaken at the suggestion of Dr. William 

 H. Park, Director, Research Laboratory, Health Depart- 

 ment, to determine whether or not the oyster could be a means of 

 infection, and, if so, under what conditions it would act in this 

 manner. The oysters were kept at the New York Aquarium, 



where all facilities were granted. 



TECHNIQUE. 



The oysters were placed in large glass jars containing about 

 8 gallons of sea water, balanced with vegetable life. The specific 

 gravity of this water varied from 1.012-1.014, which was much 

 lower than that of deep-sea water, but not very different in any 

 respect from that over the oyster beds in most localities where 

 oysters are grown for the market. 



The first tank was infected by introducing a litre of a 24-hours 

 bouillon culture of Bacillus typhosus, and thoroughly mixing it. 

 At the end of 24 hours the water in the tank was discolored, and 

 at the end of three days was very foul. The oysters were tightly 

 closed. In this first experiment there were placed in the tank, 

 besides the oysters, some soft-shell and little-neck clams. The 

 little-neck clams were as tightly closed as the oysters, but the 

 soft-shell clams had their siphons fully extended and some were 

 evidently dead, as they did not retract them on their being 

 touched, while others retracted them but slowly. 



It was evident that the tank was now unbalanced ; that is, the 

 vegetable life in it failed to give off sufficient oxygen to support 

 the animal life, and that the mollusks were rapidly dying. 



They were removed, and three oysters and two clams were ex- 

 amined. In oyster No. 1 no typhoid organisms were found. This 



