ENTRANCE OF PATHOGENIC BACTERIA 53 



cases of surgical tuberculosis in the children treated are due 

 to infection with the bovine bacillus. 



Products such as butter, 1 cream and cheese, if made from 

 tuberculous milk, can also spread the disease ; whilst diphtheria 

 and scarlet fever and many forms of diarrhoea, are commonly 

 spread in epidemic form by milk contaminated by the dairy 

 workers, and possibly sometimes from the cattle themselves. 

 Similarly, typhoid fever and cholera may be spread by milk, and 

 are often traceable to the use of contaminated water in 

 washing the dairy utensils and cans. Foot-and-mouth disease 

 can also be communicated from cattle to man by milk and its 

 products. Malta, Rock, or Mediterranean fever, a disease which 

 was formerly very prevalent among our soldiers and sailors 

 stationed in the Mediterranean, but which has been largely 

 stamped out since its etiology has become known, is chiefly 

 carried by the milk of goats, which suffer from this disease. 



Milk which contains visible filth and sediment usually con- 

 tains the actual faecal excrement of cattle, and enormous 

 numbers of bacteria, some of which, e.g. certain of the strepto- 

 cocci, are pathogenic. Most of the bacteria present, however, 

 are usually those of putrefaction, and much of the milk at 

 present distributed in large cities is really in an advanced 

 stage of bacterial decomposition. 



Some idea of the extent of bacterial infection of milk may 

 be gathered from the following tables, taken from Jordan's 

 Bacteriology, the figures given being the number of organisms 

 per cubic centimetre. 2 



MILK COLLECTED WITH GREAT CARE. 



1 In a recent investigation (Lafar : Handbuch der technischen Myko- 

 logie) 727 samples of butter were investigated and tubercle bacilli found 

 in 88 samples, or about 12 per cent. 



2 One fluid ounce equals 28 '42 cubic centimetres. One cubic centimetre 

 therefore equals roughly about a thirtieth part of an ounce. To estimate 

 the number of bacteria in a teaspoonful of milk, the above figures would 

 require to be multiplied about three and a half times. 



