ROPINESS IN WORT AND BEER 219 



of saccharose, whilst the Micrococcus also attacks maltose. The resulting mucus 

 (soluble in water, but insoluble in alcohol and ether), which has the elementary 

 formula C fi H 10 6 , is, although the chief, not the sole product of this fermentation, 

 small amounts of mannite, butyric acid, lactic acid, and carbon dioxide being 

 also formed ; and a part of the saccharose is converted into glucose. 



The so-called distilled waters (e.g. orange-flower water) often undergo 

 mucinous decomposition, some particulars of which have been reported by 

 L. VIRON (I.). As a remedy for this evil, P. Carles advised the shaking up of 

 the affected water with 2-3 grams of basic nitrate of bismuth per litre, and 

 filtering after standing. This is said to have answered particularly well with 

 orange-flower water. Ordinary distilled water is often rendered mucinous 

 by bacteria, especially when kept in wooden vessels ; A. GOLDBERG (I.) has 

 reported an instance of this kind. 



A fission fungus, Bacterium gliscrogemim, 0.57-1.1 p. long and 0.4. /x broad, 

 has been isolated by P. MALERBA and G. SANNA-SALARIS (I.) from mucinous, 

 viscid urine (which often exhibits this property as soon as voided), and has 

 been recognised as the cause of this condition. According to a research of 

 MALERBA'S (I.), the mucus (gliscrin) thereby formed is nitrogenous. 



It is well known that ink frequently becomes mucinous and viscid. M. HERY 

 (I.) investigated this matter and examined a bacterial species concerned therein. 

 As a preventive measure he recommends an addition of not less than 0.5 gram 

 of salicylic acid per litre of ink. 



C. BOERSCH (I.) made an observation, interesting to the chemist, concerning 

 a fission fungus, Sarcinaflava, capable of producing ropiness in various liquids. 

 This organism attacks fumaric acid (in acid solutions), but, on the other hand, 

 leaves the isomeric maleic acid, COOH CH=CH COOH, untouched. 



Eopiness in tan liquors is a phenomenon both well known and unwelcome to 

 the tanner, to whom it causes considerable damage and loss, since not only is the 

 liquor rendered worthless, but the hides steeped in it also suffer owing to the 

 masses of mucus adhering so firmly to the leather that great difficulty is expe- 

 rienced in getting them off again. This mucinous coating retards, or even entirely 

 prevents, the penetration of the tannin. Closer investigations regarding the 

 best means and methods of prevention would be valuable to this industry. 



166. Ropiness in Wort and Beer. 



PASTEUR (III.) was the first to study this phenomenon with the aid of the 

 microscope. He traced the cause of this complaint, which has many points in 

 common with ropiness in wine, to a fission fungus occurring abundantly in the 

 form of long chains in the affected liquids, and known by the name of Micro- 

 coccus viscosus. Morphologically, this organism greatly resembles a fission fungus 

 observed by J. BERSCH (II.) in a beer wort, which, instead of fermenting nor- 

 mally when pitched with yeast, became thick, oily, and finally viscid and ropy. 



P. LINDNER (III.) in 1889 was the first to obtain a pure culture of a viscous 

 ferment. This was a pediococcus (not specifically named) occurring in large 

 numbers in ropy white beers, a class of beverage that is particularly liable to the 

 malady. The capacities of the microbe in question are restricted to, the pro- 

 duction of ropiness in white beer wort, it being unable to do so in hopped worts 

 and beers. Hence it is perfectly innocuous and unimportant, so far as true 

 brewing, in the narrow sense of the term, is concerned. 



Other species appear in hopped beer. Two of these were found by H. VAN 

 LAER (II.) in a number of samples of ropy beer, from which they were isolated 

 to pure cultures, and named Bacillus viscosus I. and //. Both have several 

 identical characteristics, e.g. the form and dimensions of the cells, which are rod- 



