The charges for a 3-pt. seltzogene are tartaric acid 1 oz., and bicarbonate of soda 11/16oz. Any difference observable in the taste of the ready-charged syphons and of the water from the seltzogene using the charges purchased is probably due to the kind of water used, and also to the fact that a small quantity of carbonate of soda is added to the water in the syphons, whereas in the seltzogene there will be no soda in the water unless it be put in before tilling the seltzogene.