The Use of a Simple Microscope. 5 



of hot water poured upon it, which after a short time may be 

 strained off, leaving- the husks and coarser parts for examination. 

 The shining exterior of the flax seed will be conspicuous, 

 and contrast greatly with the dull husk of the cotton-seed, 

 while the farina of each may be learned by practice. Dr. Arthur 

 Hill Hassall, in his work on ' Adulterations Detected,' observes 

 that " the microscope is specially suited to the detection of 

 organised structures or substances, and that by its means one 

 kind of root, stem, or leaf may generally be distinguished from 

 another, one kind of starch or flour from another, one kind of 

 seed from another, and so on ... . The seeds even belonging 

 to different species of the same genus may frequently be dis- 

 tinguished from each other by the microscope, a point in some 

 cases of very great importance." To show the importance of 

 such discrimination, the following instance may be cited : " Some 

 cattle were fed with rape-cake, and died with symptoms of inflam- 

 mation of the stomach and bowels. Nothing of a poisonous nature 

 could be detected on analysis, but it was suspected the cake 

 might be adulterated with mustard husks, although even this 

 point could not be clearly established by chemical research. 

 Under these circumstances the cake was sent to the author (Dr. 

 Hassall) for examination, who had but little difficulty in ascer- 

 taining that it was adulterated with mustard seed, which, from 

 the large quantity consumed, was doubtless the cause of the fatal 

 inflammation. So great and manifest are the differences 

 revealed by the microscope in different vegetable substances, that 

 with ordinary care and some amount of preliminary knowledge, 

 the discrimination becomes a matter of the greatest ease and the 

 most absolute certainty." 



Manuees. 



The microscope will scarcely enable any inexperienced observer 

 to learn much of the composition or quality of manure, although 

 with practice much may undoubtedly be done. The inorganic 

 bodies, such as sand and ashes, may readily be seen. Any organic 

 substance, as sawdust, or other vegetable offal, may also be de- 

 tected ; and if a portion be washed in a very small quantity of 

 boiling water, and a drop or two of this solution then suffered to 

 dry on a glass slide, the peculiar salt or salts may be learned by 

 their form, as every particular salt, or combination of salts, has 

 its specific configuration and arrangement, which by the aid of 

 the polariscope will at once become apparent. A knowledge of 

 the form and characters of these salts is, of course, implied in 

 such an investigation. Blood, fish-offal, and other similar sub- 

 stances may likewise be made out by careful manipulation. 



