Transactions of the Royal Society of Canada 



SECTION V. 

 Series III MAY, 1919 Vol. XIII 



PRESIDENTIAL ADDRESS 



Dairy Bacteriology and its Earlier Investigators. 

 By Dr. F. C. Harrison, B.S.A., D.Sc, F.R.S.C. 



(Read May Meeting, 1919.) 



A. Kircherus in 1671 was the first investigator to observe the 

 presence of living organisms in milk. He did not attribute any 

 importance to their presence, and it is impossible now to state what 

 sort of structures they were. A few other observers in the 17th and 

 18th centuries made similar observations. Schwann, in attempting 

 to shew that fermentation was a vital phenomenon, made use of a 

 number of organic infusions and demonstrated that after application 

 of heat subsequent exposure to heated air would not start the fer- 

 mentation, thus proving that the fermentation was not a chemical 

 but a vital process. His experiments with milk were a failure, for after 

 thorough boiling he was unable to prevent milk from undergoing 

 fermentation changes. 



During the two decades, 1840 to 1860, the chemical theories of 

 Liebig were generally accepted, and the fermentation of milk sugar to 

 lactic acid was regarded as a simple oxidation. Following such a 

 theory Rowlandson advanced the following marvellous explanation 

 of the souring of milk: "When cows run their respiration is faster, 

 and this causes them to absorb more oxygen and the milk in their 

 udders is therefore oxidised faster, becomes warmer and sours more 

 quickly. Hence, the evil effects of allowing cows to run." 



Turpin, about 1840, suggested that the souring of milk was due 

 to something contained in the milk which came from the udder of the 

 cow and was probably lodged in the fat globules. Under the microscope 

 he saw somethings that sprouted from the fat globules and grew into 

 a mould, similar, if not identical, with Pénicillium glaucum. He found 

 similar growth in various dead bodies exposed to air, and he concluded 

 that it was the oxygen that caused the organisms to develop. 



Fuchs in 1841 made a real and permanent contribution to the 

 early history of dairy bacteriology. When examining sour milk he 



Sec. V, Sig. 1 



