Some interesting tables, the results of careful experiments made by an experienced carbonator, were published in the Chemist and Druggist, June, 1880, p. 253, and we append the figures here in condensed form.

A careful study of them will bring out several curious facts, as, for instance, the great waste of gas that must result from working with high pressures in the condenser. They also give very curious and unexpected results in the wide variances in the pressures retained in bottles filled at the same condenser pressure, and a further variance in the volumes of gas given out by different bottles, which show the same pressure on the testing gauge.

The former irregularity probably arises in great part from variations in the care of the bottler, as so much of the result in bottling depends on the close attention and skill of the operator.

The latter phenomenon is most likely caused by the presence of more or less atmospheric air in the gas. This is a very serious question for those who wish to produce really first-rate mineral waters, and will be alluded to further on.

We think that these experiments strongly support the opinion already expressed, that no advantage is gained by using a higher pressure than 80 lbs. to 100 lbs., but that care should be taken to see that the bottling is regular. A frequent use of the testing gauge is also desirable, to see that the pressure in the bottles is kept up to the standard.

The condensed table shows the result of several experiments on bottles, gives the number of bottles experimented on, the different pressures bottled at, actual pressures in bottles, and the number of volumes of gas to 1 of water.

Number of bottles experimented on.

Pressures bottled at.

lbs.

Mean pressure in bottle.

lbs.

Mean volume of gas.

12

120

39

3.16

10

100

34

3.

10

120

40

3.27

10

180

39

3.85

5

30

26

23

5

45

26

2.2

5

60

30.3

2 55

5

80

32.8

3.0

5

90

39.8

3.4

5

100

39.6

3.9

5

120

51

4.85

The above were bottled expressly by a well-known firm at different pressures to ascertain which gave the best result. They had six to each pressure, but kept one of each back for the purpose of pouring into a glass to try the effervescence at the different pressures, and also the pungency on the palate. In each case (with one exception) the water was well carbonated, but did not effervesce to come over the neck of the bottles. The specimen, however, which had been bottled at 120 lbs. pressure discharged the cork and came over the neck of the bottle with considerable waste.

For bottling soda-water in syphons, however, a higher pressure is needful to ensure the bottle emptying itself without being shaken, and some makers consider 200 lbs. to the square inch the proper pressure for syphon bottling. The rule, though, is a much lower pressure, say from 120 to 150 lbs.