The real value of baking-powders lies in their leavening power, or available gas. Dr. E. G. Love made an interesting examination of the brands sold in the United States, to test their comparative worth, calculating from the ordinary price of 50 cents (2s. Id) per lb., with the following results.

Name.

Cub. In. of gas per oz. of powder.

Worth per lb.

cents.

Royal (cream tartar) ..

127.4

50

Patapsco (alum) ..

125.2

49

Rumford's (phosphate) freash...

122.5

48

Rumford's (phosphate) old........

32.7

13

Hanford's none-such ..

121.6

47 3/4

Redhead's...

117.0

46

Charm (alum)...

116.9

46

Amazon (alum) ..

111.9

44

Cleveland's.............

110.8

43

Czar..........

106.8

42

Price's cream...

102.6

40

Lewis's condensed...

98.2

38 1/2

Andrew's pearl ..

93.2

36 3/4

Becker's perfect ..

92.5

36

Bulk powder..

80.5

30

Bulk aerated powder ..

75.0

29

Dr. Love regards all alum powders as very unwholesome, while the phosphate and tartaric acid powders liberate their gases too freely in process of baking, or suffer deterioration under varying cli-"matic conditions. Dr. H. A. Mott also examined no less than 42 samples of baking-powder. In the majority he found large quantities of alum, which he considers highly injurious, and in this opinion is supported by most medical men. He recommended the U.S. government to provide cream of tartar baking-powders for the Indians.

Following are recipes for compounding baking-powders: -

(1) Tartaric acid powder 8 oz. Bicarbonate soda .. 9 „ Rice flour .. .. 10 „

A teaspoonful to every 1 lb. flour.

(2) Bicarbonate soda .. 1 lb.

Farina ...... 1 „

Powdered alum .. 3/4 „

Carbonate magnesia 1/2oz.

Dry in oven separately. Magnesia may be put on the flour. Tartaric acid may replace the alum.

(3) Bicarbonate soda .. 16 oz. Tartaric acid .. .. 14 „ Carbonate magnesia 6 „ Farina ...... 12 „

Rub through a sieve.

(4) Bicarbonate soda .. 16 oz. Dry tartaric acid .. 8 „ Rice flour .. .. 12 „

(5) Dry carbonate soda 8 oz. Dry tartaric acid .. 6 „ Carbonate magnesia 2 „ Turmeric powder .. 1 „

The soda and acid are properly dried before mixing, or the powder spoils by keeping. Preserve in stoppered bottles.

(6) Sal aeratus appears to be applied indiscriminately to sodium bicarbonate, potassium bicarbonate, and ammonium carbonate.

(7) American. For making light pastry. Tartaric acid and chalk.

(8) Borwick's German is an artificial fermentation powder, compounded with coarse marze flour.

(9) Goodall's is a compound of: -

Rice flour .. .. ..2 parts.

A mixture of tartaric acid and bicarbonate of soda (each)........1 part.

(10) Horsford's. This is a powder supplied in two packets. The one contains an acid phosphate of lime and magnesia, made up with a certain quantity of flour, and the other is bicarbonate of soda, with a little chloride of potassium.

(11) Tartaric acid lb.; bicarbonate of soda and potato farina or British arrowroot (of each in powder) 3/4 lb. Separately dry them perfectly by a very gentle heat, then mix in a dry room, pass the mixture through a sieve, and at once put it into packets, observing to press it hard, and to cover it with tinfoil or close-made paper, to preserve it as much as possible from the air and moisture.

(12) Delforte's.

Powdered tartaric acid 1/4 lb.

Powdered alum ., .. 1/2 „

Bicarbonate soda .. 3/4 „

Farina........ 1 „

Dry separately, as before, mix, and further add sesquicarbonate of ammonia (in powder), 3 oz. Lastly, closely pack it in tinfoil.

(13) Green's.

Tartaric acid .. .. 35 1b. Sesquicarbonate of soda 56 „ Potato flour .. .. 1 cwt. Mix as before.

For use, 1 or 2 teaspoonfuls of baking-powder are mixed with the dry flour and other ingredients, which are then made into a dough, as quickly as possible, with cold water, and at once baked or boiled. By the addition of about 1/2 dr. of turmeric powder to each 1 lb. of the mixture it is converted into egg-powder. It should be preserved in bottles or tins, so as to prevent the absorption of moisture.

(14) Tartaric acid.. .. 1/2 lb. Bicarbonate of soda 12 oz. Starch...... 12 „

Dry each thoroughly previous to admixture, which is effected by passing through a fine sieve repeatedly; pack the powder down tightly, to prevent the absorption of moisture.

(15) Recipe No. 4 would cost, if the articles were obtained by the hundredweight, about 4d. per lb., or 1/4d. per packet. The packets are made on a block of the proper size, first rolling the paper on, then pasting down the side, and lastly the bottom, doubled neatly up. Then a box must be provided, holding half-gross packets, show-bills, etc. A half-gross box of penny packets will fetch (in London) about 3s.

(16) Bicarbonate of soda 4 oz. Tartaric acid .... 3 oz. Farina.......... 16 oz.

Mix all together. By farina is meant any cheap farinaceous material - wheat, rice, or sago flours, etc. To make the packets requires a piece of wood, say 6 in. long, for small packets, and the exact size in thickness and width that the packet is to be. The end of this piece should fit into a block of wood and go through it. Take the paper and fold it on the end of the stick, and close it at the end so as to make a square bag; now put the stick with the paper on it into the block, and withdraw the stick, leaving the paper in the block. It is more convenient to measure the powder than to weigh it. Put the powder in a small tin-plate funnel, and shake it into the paper; remove the funnel, and fold down the other end of the paper, flatten the folds with the end of the square stick and push the packet out of the block. The whole operation of making the packet should take a very short time.

(17) Ammonia has recently been selected as a superior agent in baking powders, being extremely volatile, and leaving no residue in the bread. It would seem to be most suitably employed as an acid phosphate of ammonia in conjunction with carbonate or bicarbonate of potash or of soda.