Hitherto great irregularity has existed in the methods of designating the attenuations, and as a consequence much confusion has resulted.

By some homoeopathic chemists the numbers 1, 2, 3, etc, have been used to denote the decimal scale, while others adhered to Hahnemann's plan and confined their use to centesimal preparations, using lx, 2x, 3x, etc, to denote the decimal attenuations.

A few, again, have used A to indicate lx, and B to denote 3x, these two attenuations being almost the only ones in use which could not be expressed by the centesimal numbers. The best way of avoiding all this confusion is for the homoeopathic practitioners to adopt the centesimal scale only. The reasons for this are numerous, among which the following may be noted as of themselves sufficient to decide the matter: -

1. All or nearly all employ the centesimal scale exclusively in denoting the high attenuations.

2. There are only two attenuations, viz., the 1st and 3rd decimal, which have been much used, and which could not be equally well notated centesimally.

It is necessary now to advert to a fact which is often lost sight of, and yet which is very important for all those who prescribe the low attenuations, and that is the following: -

The process of attenuation always commences from a point termed zero, and marked φ or θ; but the actual amount of medicinal substance contained in the zero differs materially, thus: -

In all instances where trituration or solution in distilled water is had recourse to, the φ represents the pure medicinal substance; e.g., Acid. Nitric. φ, Arsen. φ, Kali Iod. φ, Brom. φ, Carbo. Veg. φ, etc, always refer to the pure substance itself; and hence, in such cases, the 1st decimal attenuation contains 10 per cent. of the pure drug. On the contrary, in all cases where tinctures are made, the strong tincture, and not the crude material, is marked φ, and, as a consequence, the 1st decimal attenuation contains 10 per cent. of the tincture, and not 10 per cent. of the pure drug. Since in the present

Pharmacopoeia the proportion of 1 in 10 has been fixed, whenever possible, for the strength of the mother tincture, it follows that the 1st decimal attenuation of a mother tincture corresponds in medicinal strength to the 1st centesimal attenuation of a trituration or watery solution; and when it is impossible to make the mother tincture in the proportion of 1 in 10, the first decimal attenuation is still made to represent 1 in 100 of the drug by using a proportionate quantity of such mother tincture. For example, when the mother tincture is 1 in 15, as may happen with Belladonna or Calendula, 15 measures of such tincture would require 85 measures of the required spirit to make the first decimal.

This uniformity of strength of the mother tinctures thus gets rid of much of the uncertainty which has hitherto existed as to the actual quantity of medicine contained in these preparations; but it would have been more satisfactory to have adopted one uniform standard for all. It was found, however, after much deliberation, that a change of this kind would, for a time at least, lead to so much confusion that it has been deemed advisable not to make any such radical change.

It is very necessary to adopt a uniform use of the sign φ, since much confusion is caused by different persons employing it in different senses. The following are the rules for its application: -

1. It is used principally to denote the strongest officinal tincture, as Acon. φ, Arnica φ, Canth. φ; and these, according to the new Pharmacopoeia, have an almost uniform strength of 1 in 10.

2. It is used to denote the strongest officinal preparation of substances whose actual strength is unknown, as Caust. φ, together with the animal poisons, as Apis φ, Aranea φ, Lachesis φ, etc.

8. It should never be used to denote 1x solution of any substance in alcohol or water, when the crude substance itself has a definite chemical composition; for example, Brom. φ, Glonoine φ, Kali Iod. φ, Kreos. φ, Merc. Cor. φ, Tereb. φ, etc, should always mean the pure substances themselves, and their strongest officinal solutions should be denoted Brom. lx, Glonoine lx, Kali Iod. lx, Kreos. lx, Merc. Cor. lx, Tereb. lx, etc.

In short, the sign φ, when meaning mother tincture, should be strictly limited to the strongest solutions in alcohol of substances which have not a definite chemical composition in their crude state.

From what has been stated it will be seen that φ means the crude substance in the case of all the officinal acids, of all substances which are triturated, of all mother tinctures of vegetable and animal substances, and in the case of the following medicines, viz.: -

Alumen. Ammon. carb. Amnion. caust. Ammon. mur. Argent. nit. Arsenicum. Atropine. Atrop. sulph. Aur. mur. Bar. acet. Bar. mur. Borax. Bromium. Calc. acet. Calc. caust. Chin. sulph. Cinch. sulph. Codeine.

Copaiba. Cupr. acet. Cupr. sulph. Ferr. acet. Ferr. iod. Glonoine. Iodium. Kali bich. Kali brom. Kali carb. Kali chlor. Kali iod. Kali nit. Kreasotum. Mag. mur. Mag. sulph. Mang. acet. Merc. corr.

Morphia. Morph. acet. Morph. mur. Narcotine. Natr. carb. Natr. mur. Natr. nit. Natr. sulph. 01. animal. Phosphorus. Plat, chlor. Plumb, acet. Plumb, nit. Strychnine. Sulphur. Terebinth. Veratria. Zinc. sulph.

As regards marking the attenuations, the following plan has been adopted as the least likely to be misunderstood: -

φ. 1 / x; 1. 3 / x; 2. 5 / x; 3. 7 / x; 4. 9 / x; 5. 11 / x; 6, etc.

Or φ. 1x; 1. 3x; 2. 5x; 3. 7x; 4. 9x; 5. 11x; 6, etc.

With a view to obtain uniformity it is recommended that the second example, viz., lx, 3x, etc., etc., be the one followed by those who can do so without inconvenience.

Since only two decimal attenuations are at all frequently prescribed - namely, lx and 3x - there can be no objection to notating these A and B; but the figure with the x below or at the side is preferable, since the chemists must use the higher decimal notation to mark the intermediate steps in the process of attenuation.

It is directed that in future no chemist will send out a decimal attenuation without the x being distinctly marked; and that no practitioner will prescribe a decimal attenuation without the distinctive mark; and also that all will abstain from using the decimal notation wherever the attenuation required can be expressed centesimally; for example, that 2x shall never be used in place of 1, 4x in place of 2, 6x in place of 3, etc.

A careful attention to these simple rules will save a large amount of confusion.