160 THE AMERICAN MONTHLY [Jun 



slip the deposit which has formed in a mixture and ascer- 

 tain whether it is amorphous (perhaps mucilaginous) or 

 crystalline is but the work of a few minutes, and informa- 

 tion is gained as to the chemical incompatibility or the 

 mere precipitation of inert matter of vegetable origin. Al- 

 though the microscope may fail in some instances to solve 

 the problem forthwith, yet it very rarely happens that it 

 does not give speedy assistance in indicating the direction 

 whence the final solution will come. On one occasion a 

 parcel of citrate of iron and quinine failed to yield a bright 

 solution with water. The usual causes of cloudiness were 

 investigated without avail. A second lot was obtained 

 from the manufacturers, but it turned out equally bad,and 

 the makers could not give any explanation ; they contend- 

 ed that their methods were such as they had always 

 adopted. On submitting the carefully collected deposit to 

 the microscope it was seen to consist of ordinary dust and 

 minute fragments of straw. The manufacturers were then 

 able to trace the source of the trouble to a defect in the 

 partition, between the room in which the drug was put 

 into bottles, and the contiguous room which was used for 

 packing purposes. Doubts sometimes arise as to the cor- 

 rect dispensing of medicines, and the microscope will be 

 found of great use in helping to determine the composi- 

 tion of mixed powders and pills. 



It is so common for the pharmacist to buy his drugs in 

 the form of powder that one would think the microscope 

 would be indispensable if he is to be, as he ought to be, 

 surety for the drugs he sells. The wholesale druggists, of 

 this country are, as a class, above suspicion, and upon 

 their reputation the retail pharmacist leans with an as- 

 surance which is very praiseworthy. There is no necessi- 

 ty to say a word to shake so estimable a confidence in the 

 wholesale dealers, especially as the temptation to adul- 

 terate powdered drugs is extremely small. But the retailer 

 ought, in these days of contentious commerce, to be in a 



