164 POWDERED VEGETABLE DRUGS 



middlings. The percentages of sulphur and of charcoal are deter- 

 mined by the actual trial method. The following is the reconstructed 

 formula of the condition powder, based upon the above data. 



CONDITION POWDER 



Wheat bran 25 per cent. 



Wheat middlings 15 per cent. 



Corn meal 40 per cent. 



Sulphur 10 per cent. 



Charcoal 10 per cent. 



Total. : 100 per cent. 



Corn meal reduced to a fineness so as to make a count of the total 

 starch granules possible, gives 1,305,000,000 granules per gram. The 

 starch content of wheat, middlings varies considerably, but an average 

 article will give a starch count of 200,000,000 granules per gram. One 

 gram of sulphur will show about 140,000,000 particles per gram. The 

 number of charcoal particles per gram will depend upon the degree 

 of fineness. In the above about 350,000,000 per gram. From these 

 figures it is simple to deduce the formula given. 



The experienced microanalyst can estimate percentages with some 

 degree of accuracy by optical judgment, but such estimates will not 

 be acceptable in court proceedings. Thus, based upon the inspection 

 of an ordinary slide mount, certain face powders are declared to contain 

 about 3 per cent, of rice starch or corn starch; so-called arrowroot 

 biscuits show about 2 to 2^ per cent, of arrowroot starch; a pancake 

 flour is estimated to contain 25 per cent, buckwheat and 75 per cent, 

 wheat flour; a baking powder is estimated to contain 25 per cent, corn 

 starch; etc. This is the only method possible in cases where the 

 amount of the material is too small to permit the use of definitely 

 weighed amounts or definite volumes. This is clearly illustrated in 

 the following rather extreme and highly complex example. A bit of 

 vomit smear on a small piece of newspaper was submitted by a physi- 

 cian with the explanation that it represented a medicinal substance of 

 which he desired to know the composition. A careful microscopical 

 examination of the smear revealed the following ingredients. 



1. Starch granules and the bast cells derived from the peeled 

 roots of Althaea officinalis. 



2. Papillose epidermal cells with red coloring matter of the petals 

 oHhe red rose. 



3. Abundant globules of metallic mercury. 



4. Numerous chalk particles. 



5. A few pollen grains. 



6. Crystals of calomel. 



