1909.] Summary of Agricultural Experiments. 317 



same amount of nitrogen. The sulphate of ammonia mixture produced 

 an increase in the crop of 3 tons 4 cwt. over a plot with farmyard 

 manure only, and lime nitrogen an increase of 3 tons, so that the latter 

 proved to be nearly as efficient a source of nitrogen as the former, 



In experiments at a number of centres the effect of farmyard manure 

 alone and a smaller quantity in conjunction with artificials was com- 

 pared. The addition of 1 cwt. sulphate of ammonia, 2 cwt. super- 

 phosphate, and 1 cwt. sulphate of potash to 10 tons of farmyard manure 

 resulted in practically as good a crop as double the quantity of farmyard 

 manure without the artificials. The addition of a complete dressing of 

 artificial manures was always found to repay amply the expense of the 

 manures. 



The effect of ground lime and carbonate of magnesia when used with 

 complete artificial manures was investigated, and neither was found 

 profitable. Basic slag was also compared with superphosphate, and 

 various potassic manures were compared, but the results are described 

 as inconclusive. 



Potatoes were grown at two centres with the mixture recommended 

 in the Board's leaflet No. 80, p. 6. Satisfactory returns were obtained, 

 but at a somewhat greater cost than with two other mixtures. 



Foreign and Colonial Experiments. 



Fishy Flavour in Butter (Bureau of Animal Indust., U.S. Dept. of 

 Agric, Circ. 146, 1909). Butter, like other dairy products, sometimes 

 suffers a depreciation in value owing to the occurrence of some undesir- 

 able flavour, one of the most troublesome, though not the most 

 common, of which is that known as " fishy flavour." The matter was 

 referred to in this Journal in July, 1904, and June, 190 1, where an 

 account was given of the investigations of Mr. O'Callaghan, Dairy 

 Expert to the New South Wales Department of Agriculture. This 

 writer held that the noxious fishy flavour occasionally prevalent in 

 Australian butter was due to a small mould, Oidium lactis, which was 

 said to grow conjointly with the ordinary organism which causes the 

 souring of milk. Mr. O'Callaghan stated that he had always found the 

 organism Oidium lactis present in the fishy butter examined by him, 

 and had imparted the flavour to butter by adding pure cultures of this 

 mould to sterilised cream. . 



Since that date investigations into the subject have been conducted by 

 Mr. L. A. Rogers, Bacteriologist in the Dairy Division of the United 

 States Department of Agriculture, who observes that the various oily 

 flavours, which may be regarded as the most objectionable and trouble- 

 some flavours of butter, range from a slight suggestion of an oil to' a 

 strong flavour of machine oil. In the latter case the inferior quality of 

 the butter becomes evident even to the indifferent consumer. Fishy 

 flavour gives to butter a peculiar oily taste, suggestive of mackerel or 

 salmon, though butter is frequently described as fishy which is merely 

 oily or otherwise off flavour. The typical flavour of fishy butter, 

 however, is never mistaken for any other. In one region of the United 

 States the trouble occurs so frequently that it is spoken of in Chicago 

 as the " fishy belt." 



There are in the United States many creameries where fishy flavour 



