Transactions of RHASS Volume 1940 - Page 086
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| Year | 1940 |
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160 ANALYSES FOR MEMBERS DURING 1939. defence, and, instead of the prosecution having to prove that the milk is not as it came from the cow, the person charged must prove that it is as it came from the cow. WATERS. The proportion of samples of water of good quality was 53 per cent, and 47 per cent were of bad quality, either due to the presence of sewage or to the presence of lead, copper, and zinc. In two cases iron was found to be present in sufficient quantity to render the water unsuitable for domestic use. Samples were examined for the action of water on metal piping. One sample was found to possess the property known as temporary hardness due to the presence of 17 '4 parts per 100,000 parts, equal to 122 grains per gallon, of bicarbonate of lime. A temporary hard water can be softened by boiling, but, in large supplies, special treatment is necessary. Another sample was found to be unsuitable for domestic use owing to the presence of a fungus which was identified. Treatment of the supply was recommended in order to eliminate the fungus. When trouble of this kind occurs, the best thing to do is to clarify the liquid by means of a controlled addition of lime and alumino-ferric in a tank previous to the entry of the water to a series of settling tanks. POISONS. During the year a large number of samples of the contents of stomachs and alimentary canals and feeding-stuffs were sent in for analysis for poisons. In two cases arsenic was found to be the cause of death of heifers. Arsenic was also found to be the cause of death of a number of sheep. Lead was found in abundance in the stomach of a cow and in the stomachs of two heifers. Eight samples of feeding-stuffs were examined for poisons, with negative results. The samples sent me in connection with suspected poisoning of stock were sometimes inadequate in amount, and occasionally portions of the rumen and other parts of the alimentary canal were sent in without any contents. MISCELLANEOUS. A chemical, described by chemists as a glucoside capable of yielding prussic acid, is known to be present in wild white clover. The results of analyses of samples sent me showed that the proportion of prussic acid developed is very minute ANALYSES FOR MEMBERS DURING 1939. 161 when compared with the yield from linseed cake, which is now known with great accuracy. The average proportion found by me was 0014 per cent. Quite likely it is a useful ingredient in clover. Investigations have been carried out at various centres abroad and in this country which show a seasonal variation in the glucosidal content, the maximum amount of prussic acid developed amounting to only 0015 per cent, or about one grain to a pound of clover. Ground mineral phosphate is of great use as a fertiliser. This fertiliser contains varying proportions of fluorine. In my opinion ground mineral phosphate should not be used as a phosphatic supplement in a ration. Other sources of phosphates are available where the proportion of fluorine is minute. Fluorine is found in very small proportions in foods, including milk, and plants where no danger to health is likely to occur. The results of analyses of two samples of sheep dip show that they conform to the Regulations of the Ministry of Agriculture. It is, however, easy to buy a standard dip. Difficulties arise when the dips are diluted for use. Dilutions have been found which are stronger than those prescribed by the Ministry. These may be due to neglecting the instructions given by the manufacturers. Quite a number of cases of arsenical poisoning of sheep have occurred, and I have reported these to the Ministry, with suggestions which, if adopted, would greatly reduce the mortality of sheep due to poisoning. ‘19.: 4—4.9‘ .‘ f4 _. SH |
| Title | Transactions of RHASS Volume 1940 - Page 086 |
