DAIRY FARMING DAIRYING 439 



be '0.' Skim niilkliaviug from A to H iier ceut of fat would be '1,' and so on. Whole 

 milk Avould be of 3 grades, '3/ ' 4,' and ' 5,' and extra rich or ' fortitied' milk (to which 

 cream has been added) wonld be '9' or '10.' Cream would run from '13' to '50.' 

 No more grades of milk and cream need to he carried than is the custom now, but 

 each should be marked with its ai)])roi)riate number. While the idea of the percent- 

 age of fat thus indicated might not be clear to all, it would soon be understood that 

 the higher numbers meant the richer milk. If this practice were observed it would 

 be difficult for the drivers to tell their customers one thing and the milk inspector 

 another about the cjuality of the contents of the same can. The signs should be so 

 attached to the wagon side or can that they could not be easily changed. If bottles 

 were used the number representing the (juality should be attached to each one." 



Milk as an agency in the conveyance of disease, R. G. Freeman 

 {Med. Rec, 40 {1S96), No. IS, pp. 433-443, Jigs. 7). — The author discusses 

 the magnitude of the milk traffic and the sources of contamination of 

 milk. 



Three Petri plates 3i in. in diameter, containing a layer of sterilized 

 nutrient gelatin, were exposed for 2 minutes each on the farm of a gen- 

 tleman near ^e,w York, one being exposed out of doors, a second in the 

 barn, and a third under a cow just in front of the milk pail during 

 milking. Subsequent examination showed that the plate exposed out 

 of doors received bacteria, that exposed in the barn 111, and that 

 exposed under the cow 1,800. 



In an experiment on the effect of temperature on the growth of bac- 

 teria in milk a certain amount of milk was put in 4 sterilized test tubes 

 which were kept for 24 hours at difterent temperatures, and at the end 

 of that time plate cultures were made from a sample from each tube. 

 The following is the number of colonies which developed in each case: 

 Tube kept at 7" C. (45° F.), 45 colonies; at 10° C. (50° F.), 1,362; at 

 13° C. (55° F.), 67,170; at 20° C. (68° F.), ]34,340. 



The diseases conveyed by milk are next discussed under the headings 

 (1) Diseases conveyed by milk from a diseased cow, (2) Diseases con- 

 veyed from one human being to another by milk, and (3) Diseases 

 caused by milk which contains poisonous agents developed by bacterial 

 growth. 



The data are tabulated for 53 epidemics of typhoid fever attributed 

 to milk, 26 of scarlatina, 11 of diphtheria, 2 of foot-and-mouth disease, 

 3 of throat affection, 2 of acute poisoning by milk, and 1 of Asiatic 

 cholera. Only those occurring since 1880 are included. Cases of the 

 tiansmissiou of these diseases and of tuberculosis, anthrax, and acute 

 enteritis, and tiie danger from this transmission are discussed. 



"In summing up we may conclude that infection by milk is well established in 

 typhoid fever, scarlatina, diphtheria, tuberculosis, cholera, foot-and-moutli disease, 

 and acute enteritis, and that it may exist in anthrax. Cases of acute poisoning from 

 milk by some undetermined agent also occur. Medical literature furnishes us with 

 reliable evidence of an immense amount of sickness and a considerable death rate 

 caused by milk. The recorded epidemics are but a part of those which occur. Many 

 epidemics are never traced to their source, and some which are so traced are not 

 reported. This sickness and death directly due to contaminated milk is to a great 

 extent preventable by proper legislation concerning the inspection of dairies and 

 the handling of milk. 



