On comparing (a) and (6) it is evident that the numbers are the same in 

 both. 



(8) The prescriber intends a mixture to contain certain substances in 

 fixed portions, which will be the same in the single dose and in the bulk, 

 and will not be affected, whether the measures be stated in minims or in 

 cubic centimetres ;the numbers of minims will be larger, but the proportions 

 will be the same. The exact factors for the conversion of grams into grains 

 and of cubic centimetres into minims are 15,4324 and 16,906, respectively. 

 The procedure used in the above example is to take 16 as a near approxi- 

 mation to each of these numbers. (The extent to which this is inexact may 

 be stated as 4 drops in a teaspoonful.) Now, in ordinary prescribing, 16 

 doses is the most common of all orders, as represented by tablespoonful 

 doses of an 8-oz. mixture. If, therefore ,in such a mixture the prescriber 

 orders the numbers of minims of the drugs A, B, C, D, E in each table- 

 spoonful which he would order in a prescription in English measures, but 

 omits the symbols, and if the dispenser measures in each case the same 

 numbers of cubic centimetres into the bottle, the conversion from English 

 into Metric measures will be automatically completed. Thus it is recom- 

 mended that the practitioner who wishes to write a prescription for Metric 

 measures should simply write without symbols the drugs with the number 

 of grains or minims he intends to give in each spoonful, and that the dis- 

 penser be instructed that each prescription where no symbols are written 

 are to be dispensed in Metric measures. 



For teaspoonful doses the bulk would be 2 ozs. or 60 c.c. and for des- 

 sertspoonful doses, 4 ozs. or 120 c.c. 



(9) The following prescriptions are given in illustration: 



(a) Recipe 



Tr. Nucis Vom., 5. 

 Inf. Quass. cone, ad 60. 

 Sig. Teaspoonful in water before each meal. 



(&) Recipe 



Tr. Digitalis, 7.5. 



Spt. yEtheris, 10. 



Dec. Scoparii ad 120. 



Sig. Dessertspoonful morn, and night. 



(c) Recipe 



Ac. Hydrocyan, dil., 3. 



Liq. Morph. Mur., 10. 



Syr. Tolut., 30. 



Inf. Rosa Acid, ad 240. 



Sig. Tablespoonful thrice daily. 



135 



v 



