BY W. VV. L ESTRANGE AND R. GREIG-SMITH. 



411 



For this reason, these temperatures are k)wer than would occur 

 in practice, but even as, in the experiment, the pears and the 

 syrup were over 70°C. for at least 30 minutes, and over 85* for 

 20 minutes, the exposure was quite sufficient to pasteurise the 

 contents 



One point about the experiment was, that the tin was put 

 into the boiling water immediately the syrup was added; whereas 

 in practice, a certain time must elapse before the tin is capped, 

 put into a basket and pushed into the boiler, where it is some 

 four minutes before the zone of boiling water is reached. It was 

 considered that an interval of ten minutes would completely 

 cover this interval, and, accordingly, in another laboratory-test, 

 the container was allowed to stand for ten minutes after receiving 

 the boiling syrup, and before it was put into the boiling water. 



Even with the ten-minute interval before placing the tin in 

 the boiling water, the fruit and the syrup were well over 70° for 

 at least 25 minutes, and this should be enough to destroy all 

 vegetating yeasts and bacteria. 



A number of faulty tins, ten in all, were received in October, 

 1916. They consisted of pears, greengages, and plums. They 

 were examined bacteriologically, and no growths were obtained 

 from the contents of seven. A tin of pears contained a small 

 active yeast, Saccharoinyces Zopfii, which has been shown to be 

 responsible for the "puffing" of tins of golden syrup in America. 



