Nouns that in the nominative end in / in the genitive usually add is, as Menthol (nom.), Mentholis (gen.). In the case of these nouns the Latin and English name is usually the same, as Alcohol, Thymol, Menthol, etc.

Some add lis, as Mel (nom.), Mellis (gen.).

Nouns that in the nominative end in x in the genitive end in cis, as Nux (nom.), Nucis (gen.).

Nouns that in the nominative end in go in the genitive usually change the o to inis, as Mucilago (nom.), Mucilaginis (gen.).

Other nouns with a nominative ending in o in the genitive add nis, as Carbo (nom.), Carbonis (gen.); Sapo (nom.), Saponis (gen.); Decoctio (nom.), Decoctionis (gen.).

Some nouns with the nominative ending is in the genitive change the is to itis, as Phosphis (nom.), Phosphitis (gen.).

Others change the if to idis, as Cantharis (nom.), Cantharidis (gen.).

Others do not change in the genitive, as Digitalis (nom.), Digitalis (gen.).

Some nouns are indeclinable, as Buchu (nom.), Buchu (gen.).

The following group represents the vast majority of the needs of the prescriber:

All metals have the nominative ending um and the genitive i, as Sodium (nom.), Sodii (gen.). The Latin and English names of metals is usually the same, as Potassium, Sodium, Calcium, Lithium, etc.

All alkaloids have the nominative ending a and the genitive ae, as Morphina (nom.), Morphinae (gen.). The Latin and English names are the same except the terminations. The English name ends in ine. The Latin name is formed by changing the final e to a. The genitive (prescription) is formed by changing the final a to ae. Morphine, Morphina, Morphinae.

All glucosides and neutral principles have the nominative ending um and the genitive i, as Strophanthinum (nom.), Strophanthini (gen.). The Latin and English names are the same except the terminations. The English name ends in in. The Latin is formed by adding um. The genitive (prescription) is formed by changing the um to i. Strophanthin, Strophanthinum, Strophanthini.

All parts of all names of acids have the nominative ending um and the genitive i, as Acidum Hydrochloricum Dilutum (nom.), Acidi Hydrochlorici Diluti (gen.). The exception is the word Glaciale in Acidum Aceticum Glaciale. The Latin and English names are the same except the terminations.

In forming the Latin names of the acid radicals in salts the root is always the same.

If the English ends in ate (Sulphate) the Latin nominative ends in as (Sulphas), and the genitive (prescription) ends in atis (Sul-phatis).

If the English ends in ite (Sulphite) the Latin nominative ends in is (Sulphis), and the genitive (prescription) ends in itis (Sul-phitis).

If the English ends in ide (Bromide) the Latin nominative is formed by changing the final e to um (Bromidum), and the genitive (prescription) by changing the um to i (Bromidi).

Some exceptions to the rules given for forming the genitive, that are of interest to the prescriber, are:

Nom.

Aloe

Catechu

Folia

Fructus

Indigo

Kino

Rhus

Sassafras

Sumbul

Gen.

Aloes

Catechu

Foliorum

Fructus

Indigo

Kino

Rhois

Sassafras

Sumbul

It will be remembered that the class name of a preparation is usually abbreviated; so the following are not to be memorized, but are given as a matter of interest. It will be noted that the word root is usually the same in Latin and English, so it is usually only necessary to abbreviate the English names to have correct Latin.

The following classes of preparations have the nominative a and the genitive ae:

The following have the nominative ending urn and the genitive i:

The following have the nominative and genitive as indicated:

The adjective agrees with the noun it modifies in number, gender, and case, as Compound Tincture of Cinchona-Tinctura Cinchonae Composita. Compound Syrup of Squills-Syrupus Scillae Com-positus. Tincture of Deodorized Opium-Tinctura Opii Deodorati.

The following is a list of some of the common adjectives.

They are always abbreviated, so it is suggested that a study of terminations is not necessary.

It will be noted that usually the abbreviation of the English is also correct Latin. They are given as they appear in the names of official drugs:

Construction of Official Names.

In the names of salts the first word is the name of the base, next the acid radical, next the qualifying adjective if there is one, as:

This would read: (The) exsiccated sulphate of iron; so exsiccated and sulphate are in the nominative, while of iron is expressed by using the genitive ending. Therefore: The official name of a salt has first the name of the base, which is in the genitive; next the acid radical in the nominative; next the qualifying adjective, if there is one, in the nominative.

In the names of preparations of drugs the class to which it belongs comes first, as tinctura, syrupus, etc. The name of the particular ingredient comes next, as Squill in Syrupus Scillae. The qualifying adjective, if there is one, comes last, as compound in the Compound Syrup of Squills, Syrupus Scillae Compositus.

The above would read: (the) compound syrup of squills; so compound and syrup are in the, nominative case, while of squills is expressed by the genitive, Scillae. Therefore:

In the official names of preparations the name of the class is first and in the nominative case; next is the name of the particular drug and it is in the genitive; next is the qualifying adjective, if there is one, in the nominative.

The names of some drugs contain more than one word, when, of course, both words are in the genitive, as Tinctura Belladonnae Foliorum, Liquor Potassii Arsenitis, etc.