FARM AND DAIRY.

Taranaki Daily News, 12 April 1922, Page 8

FARM AND DAIRY.

tJNEELIABLE ANALYSIS. IN TESTING OF MILK. The unreliability of analytical evidence in the testing of milk is strikingly illustrated in a case in which a certain co-operative society in Scotland recently figured as defendants on a charge of having sold milk which was not up to the legal standard of fat. It appears the company were carrying on a large milk retail business’ several farmers supplying them with milk every morning, which was absolutely guaranteed. The milk was pasteurised and refrigerated by a most complete and up-to-date plant, installed at a cost of some £6OOO. It was then put into bottles of various sizes and sold all over the district. This bottling system was advocated by the authorities on the highest hygie-nic grounds, and several medical gentlemen pronounced the plant as one of the best they had seen. On a certain date one of the lorries was on its rounds at Valleyfield and Cutcross, and contained a large nomber of bottles of different sizes. inspector purchased two pint bottles, one in Cuteross and the other in Valleyfield. Each was divided into three parte; and one part of each sent by the inspector for analysis to Mr. Dargie, public analyst, Dundee. The second part was delivered lo defendants, and the last retained for analysis by the Government analyst, if need be. Regarding the Cuteross bottle, the results were that the inspectors part was declajed genuine, whereas the respondent’s part was certified by Mr. Dodd, analyst, Endinburgh, to contain only ’ 2.30 per cent, instead of 3 per cent. fats. No prosecution followed on the Cutcross sale. The analysis of the Valleyfield sample was still more remarkable. The inspectors’ part analysed by Mr. Dargie, was said to contain only 2.23 per cent, of fat, whereas the defendant’s part was certified by Mr. Dodd to contain 2.74 per cent, of fat. These conflicting results led the respondents to institute a number of experiments. From November 1 they took at random from one of their lorries a capsule pint bottle, and having divided it into three parts without endeavoring to mix the milk by shaking it, sent the bottles for analysis to Mr. Dargie. The result was 4.02 per cent., 3.69 per cent, and 3.07 per cent., a difference of no less than 1 per cent, in fats in the three parts. On November 9 another experiment was carried out. Two pint bottles were taken at random from a lorry. One was thoroughly shaken, and the other left unshaken. The three parts of the shaken bottle were certified by Mr. Dargie at 1.10 per cent., 2.7 d per cent., and 2.73 per cent., whilst the three parts of the unshaken bottle were certified to contain 4.31 per cent., 7.30 pe*- cent., and 1.58 per cent. From the foregoing it would seem that many a perfectly honest milk vendor could be prosecuted on a charge of defrauding the, public, not through any fault of his own, but merely through unreliable sampling.

CHEESE AND BUTTER. A BASIS OF CALCULATIONS. The secretary of the National Dairy Association has supplied the following interesting figures in connection with the disposal of dairy produce, which form a fair standard from which may be based calculations as to the value of both cheese and butter at the various prices quoted by cable: With butter at 130 s per cwt., the cost per cwt. is estimated as follows: Freight, 10 per cent., insurance 1.1 per cent., landing charges in London 1 per cent., commission 3.3 per cent., cash discount 2d in the £l, 1.1 per cent.; total 16.5 per cent, per cwt. Allowing for the cost of manufacture, 2J per lb, and an overrun of 20 per cent., the price of butterfat to supplies would be Is per lb. Calculating cheese at 86s per cwt., the cost per cwt. is estimated as follows: Freight 12.2 per cent., landing charges in London 1.3 per cent., commission 2.3 per cent., cash discount 2d in the £l, 9 per cent., shrinkage (2J per cent.) 2.3 per cent.; total, 19.9 per ewt. Allowing for cost of manufacture at 4d per lb of butter fat, and an average vield of 2.61 b of cheese to one pound of butter fat, the price to suppliers would be Is per lb of butter fat.

The cost of manufacture can only be approximate, as no doubt a factory with a very large milk supply would be better off than smaller companies.