DEFICIENT MILK.

Stratford Evening Post, Volume XXVII, Issue 3, 4 May 1915, Page 6

DEFICIENT MILK.

FREEZING TEST OF PURITY. In regard to the non-fatty solids constituents of milk, as affecting the bearing of the pure foods standard on the question of naturally poor milk as differentiated from adulterated milk, some pertinent facts are to be gleaned from a paper on "Tlie freezing point of some abnormal milks." read before the Royal Society of Queensland by Messrs J. B. Henderson, F.I.C, (Go- ' vernment Analyst) and L. A. Me.ston. • In Queensland, it may be explained, the freezing tp'st is relied upon to distinguish milk to water has been added from naturally poor milk. The paper under consideration is based upon the results of the analyses of two among several samples submitted on one day for analysis in the Covernment Chemical Laboratory, Bris? . bane, by a food inspector. One sample from a herd of six edws gave 11.6 total solids, 3.86 fat, and 7.74 solids not fat. The other, a mixed sample from two cows, gave 11.69 solids, 3.9 fat, and 7.79 solids not fat. The freezing point was .55 and .54 C respectively. The analysts point out that the fat, solids not fat, and nitrogen were all low, while the ash was just a shade above normal and the proportion of chlorine (salt) in the ash much above normal'. The freezing point was in each ease practically normal. At first glance the analytical results seemed to indicate that each milk .was a milk winch had been watered and a little comomu salt added to lower the freezing point again to normal. Added water, if calculated on the basis of normal solids not fat of 8.9 per 'cent.'in the first sample would-reach 13 per cent., while the excess of salt present in the sample would lower the freezing point to cover an addition of 12.5 per Cent, of added water. Similarly, added water •in the second «ihiple, if calculated on the 8.9 solids not fat would reach 12.5 per cent., while the'excess of salt' 'preseift would lower the freezing point to cover 12 per cent, of added water.- In each jL-ase there, was A remarkable agreement between the deduction made from the .solids not fat standard and that from the excess of salt. As. against the weight of analytical evidence for adulteration there stood the fact that the freezing point was in each case normal, and that it would probably be beyond the skill of any dairyman to exactly adjust the freezing point of the mixture of water and'milk. The attention of the Commissioner for Public Health was called to the peculiar facts of these two cases, and it was decided to investigate each case further. It was found that the samples were from tho same district. Twelve day.* after the legal samples were taken an inspector familiar with the milking of cows attended in the afternoon at each dairy, saw each cow milked and stripped," and measured and sampled the milk from each cow. A complete analysis was made ol each cow's milk. The results showed cie.ily that the samples originally received, while below the legal minimum standard'at which milk may be sold, had not been adulterated by the addition ol water. The causes of the abnormality seem to have been similar in each ease. In each the cows got most of their food by grazing on the roads md vacant lands in the vicinity, and, although tho dairies were, nearly two miles soil in the district was very poor, and the grass, .therefore, be safely taken as having been below normal. Most of the cows were i earing the. end of their period of lactation, which is recorded as the period when salty milk is generally noted. The striking feature of these results was, the investigators point out, that from eight cows, seven of them being apparently in good health, only one cow gave milk which was normal. AH the others were-.abnormal, particularly in, the high proportion of chlorine present. By far the most striking -.feature of these results was that, although the milks varied so far from tho' normal in chemical composition, the freezing point, the investigators •came to the significant conclusion that point is obviously the constant factor which should be used iii judging the purity of milk. The determination of the freezing point of liiilk is not only the most important factor which definitely settles whether or not water has been added to the milk, but is the only one which gives a close approximation to the. proportion of water which has been added.' In tlie case of bhe two samples re-1 corded, the sellers, if judged by the old solids-iiot-fnt .laniard, would certainly have been convicted for selling milk adulterated with water. As it wasthey were not prosecuted, but actio;! was taken by the Health Department to prevent the further sale of these abnormal milks to the general public." 'Why could not the same course be 'taken here in doubtfui cases, and warn the producer of poor but pure milk?