Report to the Local Government Board upon the "biological properties" of milk, both of the human species, and of cows, considered in special relation to the feeding of infants / by Janet E. Lane-Claypon.

  • Janet Lane-Claypon
Date:
1913
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Licence: In copyright

Credit: Report to the Local Government Board upon the "biological properties" of milk, both of the human species, and of cows, considered in special relation to the feeding of infants / by Janet E. Lane-Claypon. Source: Wellcome Collection.

    20/100 (page 18)
    Koiung'(^‘^) (1906) found the catalase content very variable, and showed that bacteria Avere able to produce catalase but not peroxidase, and hence concluded tljat these were two dih'erent bodies. Jensen(“^) (1906) showed that many bacteria will produce catalase, among others Staphylococcus Aureus, Proteus Vulgaris, and P. Zopfii, B. Prodigious, and Oidium Lactis. lie collected milk into sterile tubes with all precautions against bacterial contamination, and estimated the fat and bacterial (‘ontent, and the oxygen evolved from 10 cc. milk. The figures giveji on the following table show that there is a marked connection betAveen the fat and the catalase, but not betAveen the small number of bacteria and the catalase. Fat Content. Per cent. Bacteria per c.c. Oxygen from 10 c.c. Milk. Cow 1: First milk •55 160,000 Trace. Middle milk 2-70 480 •5 c.c. Strippings 8-30 360 2-0 c.c. Cow 2: First milk 1*5 3,200 •5 c c. Middle milk 3-4 2,800 10 c.c. Strippings 7-8 360 1*5 c.c. Sarthou(^^‘^) (1909 and 1910) writing against Bordas and Toup- lain {see p. 19) showed that if milk is carefully collected it contains very little catalase immediately after milking, but that on keeping the quantity increases, or, if after heating, the milk is inoculated with a lactic-acid-forming organism. Kooper(®^’ ®^) (1910 and 1911) showed that the catalase content of milk was greater on the second day after milking than it was on the first, and belie\’ed this to be due to the deA^elopment of the bacteria. If milk was collected Avith all possible precautions against bacterial contamination, the amount of catalase was mucli less, but that the content in this milk was greatly increased by the addition of a small piece of solid excreta. He also showed that boiled milk can be re-actiAmted by inoculation witli raAV milk. Faitelowitz(‘^^) (1910) agTeed Avith previous obseiwers as to the increases of catalase in milk on keeping. The addition of chloro- form or formalin inhibited the increase of catalase, which he believed to be due to bacteria. There can be little doubt that the greater part of the catalase in milk is bacterial in origin, but it is not yet ai>parent from the Avork already giA'en that this is the sole source of the catalase. Barthel(^'’) and 8midt(^^'^) (1908) working independently both showed that milk Avhich has ])een rendered sterile by the addition of antiseptics gh^es the catalase reaction, and belieA^ed this to indicate that tliere Avas a source of catalase other tlian bacteria. This missing link AA\as supplied in 1911 by the work of Rull- mann, and has been confirmed by Harden and Lane-Claypon in Avork undertaken before Pulimann’s results were published, but only actually in process of publication at tlie present time.