12i THE AMERICAN MONTHLY [May, 



BACTERIOLOGY. 



Pasteurized Milk. — All metliods of sterilization that are in 

 use in this country have the disadvantage of giving to the milk 

 the taste which is peculiar to boiled milk, and also of rendering 

 it less easily absorbed by the body. In France and Germany a 

 method has been adopted which accomplishes the purpose with- 

 out injuring the taste of the milk. Machines are in use in Paris 

 and some other cities which will heat great quantities of milk to 

 a temperature of about 155'' Fahr. for a few minutes, and then 

 cool it rapidly to a low temperature. The method has been 

 called the pasteurization of milk. It does not kill all the bacteria, 

 but it does destroy so many of them that it greatly increases the 

 keeping properties of the milk. Moreover, it almost entirely de- 

 stro3S the danger from disease-germs in milk, since nearly all 

 forms likely to occur in milk are killed by this temperature. The 

 advantage of this'method is that the temperature of 155° Fahr. 

 does not give to the milk the taste of boiled milk, which most 

 people find unpleasant, and does not render the milk ditlicult of 

 digestion. These pasteurizing machines have not yet been intro- 

 duced into this country, and the opportunity exists for some one 

 to develop a thriving business by furnishing pasteurized milk in 

 our large cities. A little experience with its superior keeping 

 properties and a little knowledge of its great wholesomeness 

 would soon create a demand for it in America, as it has already 

 done in the larger cities of France and Germany. — Fro7n Bac- 

 teria in our Dairy Products^ by Prof. H. W. Conn., in The 

 Popular Science Moiithly for April. 



A Bacterial Disease of the Potato. — This disease was first 

 noted by Prof. T. J. Burrill, of Illinois; the same rot of the tu- 

 bers has been described by B. D. Halsted. 



The rot is believed to be due to a specific organism. It shows 

 itself by a wilting and premature dying of the vines, preventing 

 in the immature condition of the tubers their further develop- 

 ment, or causing their destruction in the soil through decay. Tu- 

 bers thus decayed give ofi" an extremely otfensive odor, become 

 soft and mushy within, and emit a milky matter from places where 

 the skin has been injured. In the former case the decaying tu- 

 bers have a strong earthly smell so distinct from the other that 

 there is no danger of confusing them. 



The question of treatment is one upon which no positive infor- 

 mation can be given. It has been claimed that the trouble can 

 be held in check with the Bordeaux mixture. This, however, 

 was not the case in certain experiments in which several potato 

 plots were sprayed throughout tlie season with the Bordeaux 

 mixture, but in spite of lieavy applications the plants went down 

 completely before the tubers were the size of walnuts. 



