29 U. S. BUREAU OF FISHERIES 
to investigate this problem. The immediate purpose of the investi- 
gation was to determine the maximum length of time oysters could be 
kept in a fresh unfrozen condition and to study the effects of freezing 
and cold storage of frozen oysters, as indicated by the quality and 
keeping properties of the thawed product. Inasmuch as our Seattle 
technological laboratory was not equipped for this type of work, H. C. 
Diehl, in charge of the Frozen Pack laboratory of the Bureau of Chem- 
istry and Soils, United States Department of Agriculture, extended to 
our technologist the use of its facilities at the Spokane Street Terminal 
of the Seattle Port Commission. 
The results of this study indicated that: (1) If fresh oysters of 
maximum quality are packed in ice in airtight containers they will 
remain in good condition for not more than 10 to 12 days, provided 
the container is in sufficiently good contact with the ice to maintain 
the contents at 32° F.; (2) there is a possibility of further extending the 
freshness of unfrozen oysters if kept between 30 to 31° F.; (3) oysters 
freeze at a temperature of between 29 and 30° F.; (4) oysters frozen 
in closed containers in brine at 0° F., and in air at —25° F. appeared 
to be in good condition when thawed after 6 weeks and kept fresh 
for about 5 days; (5) oysters of poor quality when frozen and thawed 
dripped considerably and presented an unappetizing appearance. 
Unfortunately, we were not able to continue the storage studies 
beyond a period of 6 weeks because the technologist carrying on the 
work resigned. In view of this, the data obtained can be considered 
as indicative only and in no sense conclusive. 
BACTERIOLOGICAL STUDIES 
Our bacteriological studies have been closely correlated with other 
investigations of our technological staff as many of the latter investi- 
gations require a knowledge of the action of bacteria. These studies 
have included examinations of the experimental packs of canned 
fishery products to determine which processes produce sterility; 
bacterial counts on samples used in experiments on freezing oysters; 
studies of the role of bacteria in the different types of decomposition 
or spoilage described in preceding paragraphs, with special reference 
to the studies on mackerel; determinations of the effectiveness of 
formaldehyde and other chemical preservatives in pr ‘eventing or re- 
tarding the development of bacterial spoilage in fishery byproducts; 
and other miscellaneous bacterial control problems. 
DISINFECTANTS FOR SPONGES 
As described in the 1935 report of this Division, at the request of 
the sponge industry, two student assistants employed by the Na- 
tional Youth Administration were assigned through the courtesy of 
George Washington University, Washington, D. C., in 1934, to develop 
a simple and inexpensive disinfectant which could be used for steriliz- 
ing sponges after use. This study was carried on during 1935 and until 
June 1936 in the laboratories of George Washington University as a 
cooperative inv estigation of this Bureau and of that institution. A 
disinfectant, consisting of a mixture of 1 percent of formalin, 1 per- 
cent of phenol, and 0.5 percent of chlorine solution in water has been 
found to be effective in sterilizing sponges for the purpose described 
above. This disinfectant could be prepared by the housewife or it 
could be compounded by any drug store for sale along with sponges. 
