Britain at Work
A Pictorial Description of Our National Industries

34§ BRITAIN AT WORK. Photo: Cassell & Co., Lid. AT WORK IN THE LABORATORY (AYLESBURY DAIRY COMPANY). constantly moving about on the rounds, and will unexpectedly swoop down upon a cart, helping himself to a sample of the milk then in process of delivery, for the purposes of analysis. But now let us take a peep into the laboratory. The apartment is filled with bottles of chemicals and analytical parapher- nalia. The “ doctor,” as the analyst is generally called, is busy among the bottles. What happens when a sample of milk reaches his hands ? The specific gravity is at once obtained with the aid of the lacto- meter ; the temperature is also taken, with a standard of 6o°. The “doctor” next tests for fat. A little sulphuric acid is poured into a graduated glass vessel, with a narrow neck ; then eleven cubic centimetres of milk and one cubic centimetre of fusel oil are added. The vessel is tightly corked, well shaken, and placed in a centrifugal machine for five minutes. The acid dissolves everything but the fat, which floats about in globules. The action of the centrifugal machine causes these to rise to the top and form into a layer. Then, by comparing the solids which are fat and the solids which are not fat with the specific gravity, a result is arrived at which should agree, or nearly so, with a registered standard. If it does not, then the milk has been watered, and in all probability there is trouble brewing for somebody. All the sample cans containing milk thus tested bear the name of the farm from which the milk in bulk has come, so there is no difficulty in locating the source of the adulteration. It is in this laboratory also that the water from the farms is tested. It sometimes happens that the water is found wrong at a farm which has been supplying milk for some time. The last consignment so received is naturally open to suspicion, so, in order to make it perfectly safe, it is sterilised, and converted into butter. The supply is also discontinued from this particular farm until the water is put right, or should the farmer refuse or be unable to rectify it the contract is at once concluded. These precautionary measures sometimes lead to threatened actions for damages on the part of angry farmers, but