128 KEVIEW — TKOPICAL MEDICINE, ETC. 



Milk— A recent work by Kenelm Winslow, worthy of attention, is " The Production and 



continued Handling of Clean Milk," in which the use of paper bottles is suggested as a means whereby 

 much of the present trouble and expense in bottling milk would be obviated. 



A point likely to be of considerable importance in the Tropics is brought out by 

 Eomer and Much,'* who discuss a non-bacterial cause for the deterioration of milk. They 

 found : — 



That milk which had been sterilised by the combined hydrogen peroxide and perhydrase treatment regularly 

 acquired .iu unpleasant odour and taste if allowed to stand in the sunlight. Samples kept in the dark did not 

 undLTgo this change, even ai^er a cunsiderable length of time. Similar results were obtained witli raw milk, 

 with milk that had been sterilised by steam, and with the powder of milk dried in vacuo. The cause for this 

 peculiar change could therefore be neither a bacterium nor an enzyme. Further experiments showed that the 

 change only occurred if sunlight and oxygen together were allowed to act on the milk. An idea as to the rapidity 

 with which the deterioration sets in may be obtained from the following figures:— A flask of milk exposed to 

 direct sunlight was spoiled after twenty minutes ; another flask exposed to diffused daylight, only after five days ; 

 a third sample kept in the dark was good after a fortnight. The blue, violet and ultra-violet rays proved to be 

 most active in inducing the change. This fact may become important in view of the recent suggestion to sterilise 

 milk by the use of ultra-violet light. 



With regard to the chemical nature of the phenomenon, it .appears that only the cream undergoes the change, 

 whilst solutions of the milk-casein and whey do not show it. Now, it was proved by Ritsert, in 1890, that the 

 " rancidity " of butter-fat is due not so much to a bacterial action as to the combined effect of light and air. 

 More detailed work by Jensen proved that the bacteria are mainly responsible for the hydrolytie change (acid 

 production, "true rancidity"), but that sunlight and air have a marked cxidising effect, which is chemically 

 evident by a decrease of the iodine number (" tallowy change "). 



The authors confirmed these results in their experiments, and point out the danger 

 incurred, especially by infants' milk which is usually bottled and which may be often seen 

 exposed to the sun. 



This doubtless accounts for the peculiar taste which milk sometimes acquires in 

 Khartoum, and which, I think, has sometimes been attributed to the goat when faulty 

 storage was the true cause. 



Mettam- deals with " Diseases of the Udder and the Milk Supply," pointing out that 

 the mammary gland may be attacked by tuberculosis, actinomycosis, and botriomycosis, as 

 well as by the more general organisms of suppuration. There is also a form of mastitis due 

 to a streptococcus which is contagious, and though, according to Mettam, this streptococcus 

 is not pathogenic for man, still the idea of drinking milk containing many streptococci is 

 repellent. 



He notes, however, that in acute mastitis the changes in the secretion and in the 

 secretion gland are so marked that no sane owner of dairy stock would think for a moment 

 of adding what he may obtain from the gland to the general output. As regards cow-pox, 

 he thinks it would be dangerous to permit the distribution of the milk, because of the 

 possibility of its becoming contaminated by lesions in the sinuses of the udder and the risk 

 of children of tender age becoming infected by drinking the milk in a raw condition. He 

 mentions the remarkable case of brown scabs upon the teats and udders of a cow, due in 

 all probability to infection with organisms of human diphtheria, for a bacillus exactly 

 resembling the Klebs-LoBffler organism was isolated from the lesions. Probably the local 

 infection was of human origin. 



There is a good deal said about tuberculosis which really comes under the heading 

 " Veterinary Diseases " (page 217j, but mention may be made of the four methods employed 

 for arriving at an opinion as to the condition of the udder. These are : — 



(1) The application of tuberculin ; (2) manual examination of the udder .and its glands; (3) examination of 

 the secretion by (n) microscopic examination after sedimentation and approximate staining, {b) animal 

 experimentation ; (4) harpooning the quarter and withdrawing a portion of the affected gland for examination. 



(1) Application of the tuberculin test will only give a general reaction, and the knowledge gained from 

 the results following its use will only be of value if the clinical evidence (2) is beyond doubt. It is not possible 

 to ascertain during life unequivocal evidence of any local reaction. 



• Romer and Much (1906), Bcrl. Klin. IVoch., Nos. 30 and 31, quoted m Journal of Prcxxniivc Medicine, 

 October, 1906, Vol. XIV. 



= Mettam, A. E. (January, 1907), " Diseases of the Udder and the Milk Supply." Journal of the Moiial 

 InsliluU of Public Health, Vol.'XV. 



• Article not consulted in the original. 



