96 PRESCRIPTION WRITING 



(3) All other Latin names of drugs, of whatever ter- 

 mination (except those ending as described under rules 1 

 and 2) have their genitive in s smd is. 



The genitive case can be formed in practice, in some 

 instances, by adding is to the nominative, as, for example, 

 chloral, genitive chloral-is ; aether, genitive aether-is. To 

 many nouns ending in the nominative in as or is, we not 

 only add is to the nominative, but also change the latter 

 letter of the nominative case. For instance, to sulphas 

 (sulphate) not only do we add is, salphas-is, but we change 

 the latter letter, s, of sulphas into a t, so that the proper 

 genitive of sulphas is sulphat-is. 



The same remark applies to all the other Latin names of 

 salts, as sulphis, genitive sulphit-is ; nitras, genitive nitrat-is ; 

 hydrochloras, genitive hydrochlorat-is ; citras, genitive 

 citrat-is ; phosphas, genitive phosphat-is ; acetas, genitive 

 acetat-is. Cortex is not cortex-is in the genitive, but corticis. 

 Mas, genitive not mas-is, but maris. Adeps, genitive not 

 adeps-is, but adipis. Mucilago, pepo and pulvis lengthen 

 and change in the genitive to mucilagin-is, pepon-is and 

 pulver-is. Aloe, genitive not aloeis, but aloes, adding s and 

 not is. 



(4) Some Latin names of drugs do not change their 

 ending in the genitive because indeclinable and not latinized^ 

 or else they belong to the fourth declension, where the 

 genitive case is the same as the nominative. Examples : 

 Spiritus, quercus and fructus, already mentioned, as excep- 

 tions to rule 2. Cannabis, digitalis, sinapis and hydrastis. 

 The genitive of these nouns is the same as the nominative. 



The following are indeclinable : Amyl, buchu, catechu, 

 coca, curare, jaborandi, kino, phenol, salol, naphtol, thymol, 

 menthol, cusso, etc. 



If the Latin names for quantities, and amounts thereof 

 are written out in fall (instead of using signs for quantities, 

 and numbers for the amounts), the quantities and amounts 

 in Latin must be put into the accusative case, as they are 

 the objects of the verb, recipe. 



