102 THE AMERICAN MONTHLY [April, 



BACTERIOLOGY. 



A Bacteriological Examination of the Boston Milk Sup- 

 ply. — Professors Sedgwick and Batchelder. of tlie Massachusetts 

 Institute of Technology, have reported in the Boston. Medical 

 and Surgical Journal some results of their work. 



They declare that the so-called " pure " milks, even when not 

 tampered with, were found to swarm with millions of these micro- 

 scopic vegetables to every teaspoonful. the eflect of which alwavs 

 must be to produce sourness and chemical decomposition. 



In milk as it came from the cow they could find no bacteria, 

 though special means were necessary in order to prevent infection 

 during the milking process. The silver catheter of veterinarians 

 was used, it first having been sterilized by heat and brought to 

 the stable in a plugged test tube. The receptacle also was steril- 

 ized. It was shovyn beyond a doubt that healthy cows give milk 

 absolutely free from bacteria. 



The trouble was found to arise from particles of dirt and filth 

 getting into the pail during the milking process. Such pollution 

 is proved to be general by the bacterial tests. Once introduced 

 the bacteria multiply enormously, and souring follows early. 



Milk drawn with great care but by hand was found to contain 

 ^30 bacteria per c.c. That drawn in the ordinary manner but by 

 the average milkman contained 30,500 per c.c. Of that which 

 had stood several hours, the average of 15 samples gave 69,143 

 per c.c. Of 57 samples taken from peddlers the average was 

 2.355,500 per c.c. Of 16 samples from grocers, who usually 

 hold it on hand longer than the peddlers, the average was 4,577.- 

 000 per c.c. An extreme case of railroaded milk had in it 5,- 

 664,000 per c.c. 



They speak in plain terms of the need of inspection to prevent 

 pollution quite as much as to prevent adulteration. Improvement 

 in milkmen and in receptacles is very urgent. That well people 

 may consume large quantities of such milk without injury is ad- 

 mitted, but that infants and invalids suffer therefrom seems to be 

 of little doubt. Thus, though indirectly, do we find again the 

 microscope to be one of the civilizers of the age. 



A New Bacterium. — L. Perdrix has separted from Paris 

 water a bacillus. B. aynylozyfjiicus, which ferments starch with 

 production of amyl alcohol. It is separated by culture in potato 

 and finally on gelatine. It grows onlv in the absence of oxygen. 

 Fuller description maybe found in Attn. Inst. Pasteur., 1S91, No. 

 5, and a translation in your. Chein. Sac, 1892, p. 90. 



Bacteria in Street-dust, — Dust from the streets of Naples 

 yielded 761 ,541 ,000 micro-organisms per gram of dust on the aver- 

 age. The filthiest street dust furnished 5,000 million per gram, 

 many of which were pathogenic germs. The regions were jDro- 

 portionately unhealthy. 



