Dr. Elwyn Waller found the following variations in the constituents of pure butter:--Fat, from 83 to 85; water, from 8 to 10; curd, from 1 to 3; salts, from 3 to 5 per cent. Butter fat fuses at 28° to 37°, and at 37°·7 its specific gravity ranges from 0·91200 to 0·91400. The most common adulterations of butter consist in the addition of water, salt, colouring matters, and various foreign fats (notably oleomargarine). The first two admixtures are easily recognised by the proximate analysis; the detection of the last sophistication involves a somewhat elaborate examination of the fatty constituents of the butter. -----------------+--------+---------------------+--------------------- | No. | Water. | Fats. Analyst. | of |------+------+-------+-------+-------+----- |Samples.| Max. | Min. | Avg. | Max. | Min. | Avg. -----------------+--------+------+------+-------+-------+-------+----- | p.c. | p.c. | p.c. | p.c. | p.c. | p.c. | p.c. König | 123 |35·12 | 5·50 | 14·49 |85·25 |76·37 |83·27 Bell | 117 |20·75 | 4·15 | 14·2 | .. | .. | .. | | | | | | | Hassall { | 48 |15·43 | 4·18 | .. |96·93 |67·72 | .. { | |28·6 | 8·48 | .. |96·93 |67·72 | .. | | | | | | | Angell and Hehner| 30 |16·0 | 6·4 | .. |90·2 |76·4 | .. Wanklyn | 50 |24·9 | 8·6 | .. | .. | .. | .. Caldwell | 26 |30·75 |10·45 | .. | .. | .. | .. Ellis | 12 |10·5 | 4·9 | .. |89·7 |80·8 | .. Larue | 12 |16·5 | 8·0 | .. |86·9 |79·14 | .. | | | | | | | Fleischman {fresh| .. | .. | .. | 18·0 | .. | .. |80·0 {salt | .. | .. | .. | 12·0 | .. | .. |83·5 | | | | | | | Blyth | 5 |12·984| 8·58 | .. |87·223 |82·643 |85·45 Schacht | 8 | 9·00 | 1·25 | .. |98·00 |87·00 | .. -----------------+--------+------+------+-------+-------+-------+-----