increasing the average liability to disease (especially to infectious disease), and shortening the duration of life.

3. Total abstainers, other conditions being similar, can perform more work, possess greater powers of endurance, have on the average less sickness, and recover more quickly than non-abstainers, especially from infectious disease, whilst they altogether escape diseases specially caused by alcohol.

4. All the bodily functions of man, as of every other animal, are best performed in the absence of alcohol, and any supposed experience to the contrary is founded on delusion, a result of the action of alcohol on the nerve centres.

5. Further, alcohol tends to produce in the offspring of drinkers an unstable nervous system, lowering them mentally, morally, and physically. Thus deterioration of the race threatens us, and this is likely to be greatly accelerated by the alarming increase of drinking among women, who have hitherto been little addicted to this vice. Since the mothers of the coming generation are thus involved, the importance and danger of this increase cannot be exaggerated.

In conclusion, the manifesto states that, as the common use of alcoholic beverages is always and everywhere followed, sooner or later, by moral, physical, and social results of a most serious and threatening character, and that it is the cause, direct or indirect, of a very large proportion of the poverty, suffering, vice, crime, lunacy, disease, and death, not only in the case of those who take such beverages but in the case of others who are unavoidably associated with them, the signatories feel compelled to urge the general adoption of total abstinence from all intoxicating liquors as beverages, as the surest, simplest, and quickest methods of removing the evils which necessarily result from their use.

PRACTICAL WORK ON CHAPTER IV.

I. VINEGAR.

1. Pour some wine or beer into a beaker and leave it exposed to the air for a few days. The liquid gradually develops a sour taste and will turn blue litmus paper red, showing that an acid has been produced.

2. Obtain some vinegar, note its colour, taste, and smell. Test its reaction with litmus paper.

3. To estimate the acidity of vinegar. Take 25 c.c. of vinegar, dilute it with distilled water until its volume is exactly 250 c.c. Take 25 c.c. of this liquid, add a few drops of phenolphthalein as an indicator, and run in a decinormal solution of soda, i.e. a solution containing 4 grammes of caustic soda per litre, until the last drop produces the characteristic colour with the plenolphthalein. The number of c.c. of soda required x 006 x 100 = percentage of acetic acid in the vinegar.

4. To test for sulphuric acid in vinegar. To a small quantity of vinegar in a test tube add a few drops of nitric acid and then some solution of barium chloride. If a precipitate is produced, the presence of sulphuric acid is shown.

1. Test for turmeric by adding a little ammonium hydrate solution to some mustard. If the yellow colour changes to a brownish-red the presence of turmeric is proved.

2. Mix a little mustard with water, and then add several times its bulk of boiling water. Then add one drop of solution of iodine. A blue colour shows the presence of starch.

III. PEPPER.

Pour a small quantity of pepper into a dry test tube and then add sufficient strong hydrochloric acid to cover it well. If the sample is pure pepper it acquires an intense yellow colour, and most of the adulterations can easily be detected by remaining uncoloured.

IV. TEA.

1. Examine the leaves. Pour some hot water over one or two of the larger leaves. They should uncurl quickly when thus treated. Now spread them out between glass slides and hold them up to the light. The characteristics of the leaves should agree with those described on p. 93.

2. To test for tannin. To some strong tea in a test tube add a few drops of ferric chloride solution. An inky liquid is formed showing the presence of tannin.

3. To estimate the tannin. Weigh out 2 grammes of the powdered tea into a small dry flask; cover with 100 c.c. distilled water, and boil for 1 hour. Filter while hot. Pour over the residue another 100 c.c.

of boiling water and filter this through the same paper. Receive both filtrates in the same beaker. To the clear liquid add a solution of gelatin until no more precipitate is produced. Filter the liquid through a weighed filter paper, dry the precipitate in an oven at about 120° C., and weigh when quite dry. The tannin may be taken to be 40 per cent. of the dried precipitate. Calculate the percentage of tannin in the sample of the tea taken. (This method gives only an approximate result.)

4. To estimate the ash. Take 10 grammes of tea, place in a weighed dry porcelain or platinum dish, and gently heat with the Bunsen flame until it is reduced to an ash, which is generally grey or greenish in colour. Cool and weigh again. Calculate the percentage of ash in tea. It should be between 4 and 6 per cent. In faced teas the ash may be 10 per cent., while in "lie tea" it may reach 30 per

cent.

Partly fill the dish with boiling water, stir with glass rod and pour into a filter. Wash out the dish with more boiling water, passing each washing through the filter. The hot water dissolves the soluble part of the ash, while the insoluble part remains on the filter paper. Place the filter paper and its contents in a weighed platinum crucible and heat until the contents are reduced to a fine ash again; cool and weigh again. Calculate the percentages of insoluble and soluble ash in tea. The soluble part of the ash should amount to half the total ash.

5. The action of tannin on proteids. Make a solution of tannin in hot water. Then dissolve some isinglass in boiling water. Add the tannin solution to the isinglass. A white precipitate is produced. This experiment illustrates the action of strong tea on any proteids, such as meat.

V. COFFEE.

1. Test a sample of coffee for chicory by the methods given on pages 94 and 95.

2. Determine the percentage of ash as in (4) above.

VI. COCOA.

1. Examine by the microscope for the starch granules of added starch.

VII. FERMENTED DRINKS.

1. Fit up the apparatus shown in fig. 28. Put in the flask sugar and water, and add some brewer's yeast. Leave it in a warm place for some hours. A clear colourless gas collects in the jar. Add some lime water and shake it up. The lime water is turned milky, showing the gas to be carbon dioxide.

2. Filter the contents of the flask, and pour the clear liquid into a retort, fitted with a condenser as in fig. 29. Note the smell of the liquid that distils over. When about a teaspoonful of the liquid has collected in the cooled receiver, pour it into a watch glass and apply a

light. The liquid burns with a pale flame, showing that alcohol has been formed.

3. Repeat experiment (2) using beer or wine for the distillation.

4. Place a very minute fragment of yeast upon a microscope slide. Add one drop of water and mix the yeast with it by means of a platinum wire. Spread the mixture evenly over the slide, cover with

Fig. 28.-FLASK FOR FERMENTATION.

a coverglass and examine it under the microscope. The yeast is seen to be composed of tiny oval bodies, each of which is a living plant, and is capable of multiplying and bringing about the conversion of sugar into alcohol and carbon dioxide.

atty

Fig. 29.-DISTILLATION APPARATUS.

5. Determine the boiling point of alcohol. To do this pour an ounce of alcohol into a Wurtz flask fitted with a condenser and having a thermometer passing through the cork so that the bulb of the thermometer is just above the surface of the alcohol. Gently heat the alcohol until it boils. The mercury in the thermometer rises up to about 78°C. and then remains stationary. The alcohol vaporised by the heat is liquified in the condenser and so none is wasted.

6. To estimate the amount of alcohol in a given liquid. About a pint of beer should be either well shaken in a large bottle and allowed to stand, or rapidly poured, "tossed," from one vessel to another. This is to expel as much of the CO2 as possible. Place 250 cc. in a retort connected with a condenser and receiver, make alkaline with caustic soda solution, aud boil gently until two-thirds of the liquid has passed over into the receiver. Then pour the distillate into a 250 c.c. flask, and add distilled water until the level of the liquid stands at the mark. Next find the density of the liquid by weighing a measured volume of it, preferably in a specific gravity bottle. Calculate the weight of 1000 c.c. of the liquid. If this weight is 1000 grammes then the beer would be free from alcohol, and the more the weight is below 1000 grammes the greater is the amount of alcohol in the beer because 1000 c.c. of alcohol weighs only 793.8 grammes. It is assumed that the whole of the alcohol in the beer has passed over when two-thirds of the liquid has distilled. Calculate the percentage of alcohol in the beer by means of the following table.

7. The acidity of beer. This is an important determination. Measure 100 c.c. of beer into a 250 c.c. flask and fill up to the mark with distilled water. Take 25 c.c. of this diluted beer, add phenolphthalein as an indicator and run in decinormal soda solution until the liquid is neutral. Not more than 3 c.c. of the decinormal soda solution should be required. The normal acidity of beer depends upon carbonic, acetic, lactic, tannic, and malic acids, but it is occasionally increased by the addition of sulphuric acid.