42 
I do not think, therefore, that the laboratory experiments, complete ; 
and painstaking though they be, should be held as establishing a ! 
standard in the case of food products where the following conditions 
would establish a strong dissimilarity of conditions: 
First. Food products are never intentionally inoculated with plague « 
organisms, or. for that matter, with any others. On the contrary, no ; 
matter how careless the operator and how slovenly the method of 
preparation, care is exercised to protect from gross contamination, j 
The product, it is true, may accidentally become contaminated by 
preparation in a dwelling where plague prevails. After preparation , 
it may become contaminated in the warehouse or store bv being 
“muzzled*’ by a rat suffering from the pneumonic form of the disease, ; 
or a plague-infected rat may nest or even die on the products, or the ; 
foods may be contaminated b}’^ dust containing virulent and viable 
plague bacilli. 
But granting any or all of these possibilities, should the contamina- | 
tion take place it is at once confronted by the following condition: 
Second. That all products for wear, for use in the arts, or for food ' 
are the seat of contamination by saprophytic bacteria, and that there 
is at once set up a conffict between the pathogene on the one hand 
and the saprophyte on the other, in which contests the hardier sapro- 
phyte usually comes off victorious over the more deadly but more 
highly organized and sensitive pathogene. 
1 repeat, therefore, that the conditions obtaining in exact labora- 
tory experimentation are not applicable to and do not form an invari- : 
able rule of conduct for quarantine matters, in which more normal 
natural conditions obtain. 
The continuation of the experiments which formed the basis for 
Dr. Rosenau’s preliminaiy note lead in the main to the .conclusion 
that if a substance is favorable for the retention of moisture, and a i\ 
comparatively low temperature (17^ to 19° C.), it will afford a good 
culture medium for the growth of the plague bacillus, unless it have 
in itself some inherent property which renders it unsuitable. This 
latter may be something added to it in the process of manufacture, as 
the sizing or lilling in certain fabrics, or the resins or gums contained 
in woods, or the bacteria which find a habitat in manufactured foods. 
Thus the plague bacillus failed to grow on linen crash until it had 
been thoroughh^ freed of its sizing by washing; on sawdust it lived 
but one day; on ffannel only three days: on a piece of carpet (the effect 
probably of the d}’e) it did not grow at all. 
The following food products were tried, and gave the following 
results: On cheese it lived from thirteen to seventeen days, but this 
only after the cheese had been thoroughly sterilized and melted; on 
rice, sterilized, three days at 22° to 29° C. ; on dried salt beef, three ^ 
