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of vessels and appliances which may be used during the handling 
of the grape or other juices. These micro-organisms belong to 
numerous species, and are classified as moulds, yeasts, and bacteria. 
They differ as regards their shape, their habits, and the resulting 
produce of their activities. Besides these living agents of decom- 
position of the juices of fruit, there are present viscous, albuminoid 
substances which cause a certain amount of turbidity in the liquid 
and make it unattractive to the sight. 
Those two factors, viz., micro-organisms and viscous albuminoid 
substances, are the two elements which the unfermented grape-juice 
preserver has to contend with, and in order to purge the liquid of 
them, two ways present themselves—one chemical and one physical. 
The chemical methods consist in paralysing the microscopic cells of 
the agents of fermentation by means of antiseptic substances. This 
method is prohibited wherever a Pure Food Act is enforced, and 
moreover, on hygienic grounds it is strongly to be deprecated, for 
the reason that such toxic substances which silence and paralyse 
the living cells of organisms in the sweet juice, on the other hand 
also happen to injuriously affect those other micro-organisms which 
accompany and foster digestion. Their use is to be deprecated, 
and should be prohibited by law. 
The physical methods are, on the other hand, safe, and yield 
results which are quite satisfactory. These are purely mechanical, 
such as filtering, or both mechanical and biological, such as those 
methods in which heat, cold, or electricity play the leading part. 
Of these, heat is, up to the present, both the cheapest and the most 
reliable. 
The germs figured in the chapter on “Ferments and on Diseases 
of Wine” consist of translucent gelatinous cells which at even a 
moderate temperature coagulate and perish. The temperature at 
which these micro-organisms perish is called “the death point” of 
these microbes. This point is several degrees lower in slightly acid 
liquids, such as grape or other fruit-juice, than it is in neutral 
liquids. Time is also a factor which in a measure influences this 
death point. For instance,-a micro-organism which would only 
perish if heated for half an hour at, say, 60deg. C. (140deg. F.) 
would probably survive the treatment if the period of heating was 
only a quarter of an hour. Then again, micro-organisms occur in 
two states: an active or growing state, consisting of a fragment of 
protoplasma, encased in a cellulose covering, and a resting or spore 
state, the spores being minute nuclei embedded into the body of the 
micro-organism and endowed with greater resistant properties. This 
being so, a degree of heat which would coagulate and kill the micro- 
organism in its gellified or growing state would probably only cause 
passing discomfort to the more hardened resting spores. As a rule, 
it requires about 5deg. C. (9deg. F.) additional above the death 
