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.

    12/100 (page 10)
    for the peroxidase reaction, and that the intensity of the action VO l ied with tlie concentration of the salt. He believed the giiaiac test to be entirely unreliable. Sarthoii( and Sartory(^^^) (1911) both pointed out the same facts. Sartory worked with the water of ]Jreuil and showed that this mineral water even after being bottled tor two years will still give the peroxidase reaction with guaiac and hydrogen peroxide, and has catalytic properties. There is no difficulty in supposing that tlie salts of iron and possibly manganese are concerned in the peroxidase reaction in milk. It has been shown that Grimmer found these last two metals in the solution made by him from milk, and iron is well known to be constantly present in both human and cows’ milk, but I am unaware of any evidence as to the condition of the metal, whether colloidal or not. The most recent work upon the iron in milk is that of Langstein(^^) (1911), in whose paper further references can be found. Several authors have shown that the peroxidase reaction depends upon the alkalinity of the milk. Thus Kooiier(^^) (1910) and Hesse and Kooper(^^) (1911) showed that as the acidity of milk increased the peroxidase reaction became weaker. They worked with Hothenfusser’s reagent and showed that the alkalinity of the milk decreases on boiling and the reaction disappears. It, however, a little alkali is now added the reaction at once returns. This is, however, not the case if the alkali is added before boiling; in this case the alkali appears to be bound, for the total alkalinity is decreased, and the reaction is not given. Grimmer(^^) (1911 and 1912) did not entirely agree with Hesse and Hooper, for he found that if the milk is heated above 100° C. the addition of ammonia did not restore the reaction. He prepared a solution by dissolving the precipitate obtained by the complete saturation of whey with ammonium sulphate and found that this gave a strong peroxidase reaction. He concludes that the ferment must either be of the nature of lact-albumin or that it must be absorbed by the protein. The reaction w’as abolished if the alkalinity of the solution was raised to that of a soda solution. The ferment action was also entirely destroyed by digestion with either pepsin or trypsin. One more point remains for consideration which has been already mentioned on p. 6, namely, that of the relation of the peroxidase to a peroxide. Neumann-Wender(^^°) (1903) found that active guaiac tincture, that is, one giving the direct ” oxidase reaction, was inactivate by boiling, and he believed that the active tincture contained a peroxide. That this is the case was definitely shown by the work of both Arnost(^) (1905) and Waentig(^“^) (1907). Giiaiacum contains a substance which be- comes oxidised on exposure to the air, and forms a peroxide. If this substance is formed in sufficient quantity the tincture is active,” and the peroxidase reaction is given without the addition of hydrogen peroxide. When giiaiacum is digested with acetone, as was done by Siegfeld in making his active solution, this substance is formed. The work of Bach and Chodat has been mentioned already on p. 6. From their work and from that of Moore and Whitley(^^^)