(5) _Slimy Fermentation._ This graphic but inelegant word is used to denote an increased viscosity in milk, and its tendency when being poured to become ropy and fall in strings. Such a condition deprives the milk of its use in the making of certain cheeses, whilst in other cases it favours the process. In Holland, for example, in the manufacture of Edam cheese, this "slimy" fermentation is desired. _Tættemœlk_, a popular beverage in Norway, is made from milk that has been infected with the leaves of the common butter wort, _Pinguicula vulgaris_, from which Weigmann separated a bacillus possessing the power of setting up slimy fermentation. There are, perhaps, as many as a dozen species of bacteria which have in a greater or less degree the power of setting up this kind of fermentation. In 1882 Schmidt isolated the _Micrococcus viscosus_, which occurs in chains and rosaries, affecting the milk-sugar. It grows at blood-heat, and is not easily destroyed by cold. Its effect on various sugars is the same. The _M. Freudenreichii_, the specific micro-organism of "ropiness" in milk, is a large, non-motile, liquefying coccus, which can produce its result in milk within five hours. On account of its resistance to drying, it is difficult to eradicate when once it makes its appearance in a dairy. The organism used in making Edam cheese is the _Streptococcus Hollandicus_, and in hot milk it can produce ropiness in one day. A number of bacilli have been detected by several observers and classified as slime fermentation bacteria. The _Bacillus lactis pituitosi_, a slightly curved, non-liquefying rod, which is said to produce a characteristic odour, in addition to causing ropiness, brings about some acidity. _B. lactis viscosus_ is slow in starting its fermentation, but maintains its action for as long as a month. Many of the above organisms, with others, produce "slimy" fermentation in alcoholic beverages as well as in milk. (6) _Soapy Milk._ This is still another form of fermentation, the etiology of which has been elucidated by Weigmann. The _Bacillus saponacei_ imparts to milk a peculiar soapy flavour. It was detected in the straw of the bedding and hay of the fodder, and from such sources may infect the milk. There is little or no coagulation. (7) _Chromogenic Changes._ We have already remarked that colour is the natural and apparently only product of many of the innocent bacteria. They put out their strength, so to speak, in the production of bright colours. The chief colours produced by germs in milk are as follows: