122 



THE AMERICAN MONTHLY 



['July, 



It consists, as shown in Figs. 25 and 

 26, of an ordinary wide-mouth bottle 

 or fruit-jar, having a number of holes 

 (Fig. 25) half an inch, or more, in 

 diameter, bored through the side, at a 

 distance from the bottom corres- 

 ponding to the capacity of the bottles 

 in which the collector intends to 

 bring home his material. Over the 

 holes, and around the bottle, is tight- 

 ly tied, or laced (Fig. 26), a piece of 

 fine muslin, which should be at least 

 three times as wide as the holes in 

 the bottle. Over the muslin, both 

 above and below the holes, a rubber 

 is placed so as to make all water 

 tight, except at the points corres- 

 ponding to the holes. 



Now, any quantity of water may 

 be poured into the bottle, and it will 

 rapidly run out through the muslin 

 covering the holes, leaving the organ- 

 isms which it contained in the bot- 

 tle, together with only so much water 

 as the lower part of the bottle, below 

 the holes, will hold. This can then 

 be poured into smaller bottles for 

 transportation, by so inclining the 

 collecting bottle as to allow its con- 

 tents to run out on the unperforated 

 side. More straining surface can thus 

 be gained, and the nuisance of funnels 

 (necessary in the Wright's form) be 

 dispensed with. 



The principle upon which this 

 bottle is constructed is subject to a 

 variety of modifications. 



For instance, a slit of any width, 

 from half to one inch, may be filed in 

 the side of a fruit jar, and thus addi- 

 tional straining surface be gained ; 

 or, a tin or zinc can may be used, 

 having a broad slit in its side over 

 which the muslin can be stretched. 



If it is preferred to have the 

 strainer inside the vessel, this can be 

 easily arranged by using a vessel 

 with a slit, and placing a diaphragm 

 of thin iron (ferrotype plate) inside, 

 somewhat wider and longer than the 

 slit in the vessel, and having in its 

 centre a slit of the same size as that 

 in the vessel used. 



A piece of muslin can be drawn 



over the diaphragm, covering its side 

 next the interior of the vessel and 

 passing over the edges, thence up- 

 wards, downwards, and laterally 

 through the slit in the vessel and 

 around the outside of the same, as in 

 the former case, rubber bands being 

 applied as before over the upper and 

 under edges of the muslin, 1 do not 

 think there is any particular advan- 

 tage to be gained by this mode of 

 construction, but it is suggested as a 

 modification which may be deemed 

 desirable by some. It is necessary 

 that the holes in the vessel be bored 

 at some distance from the top of the 

 bottle, in order to get sufficient 

 weight of water to force itself rapidly 

 through the strainer. If the holes 

 are made near the top of the vessel, 

 it will not work much more rapidly 

 than the Wright's form, although 

 even in that case the absence of fun- 

 nels is a great convenience. 



The Detection of Adulteration 

 in Food. 



BY C. M. VORCE, F. R. M. S. 



III.— Tea. 



In examining a sample of tea for 

 adulteration, the first process is to 

 sift it, or to otherwise separate the 

 fine dust from the leaves, etc. Hav- 

 ing done this, put a quantity of the 

 leaves to soak in some warm water. 

 On examining the dry dust with the 

 microscope, if the tea was good, we 

 shall find the dust to be almost en- 

 tirely composed of fine fragments of 

 the leaves, detached hairs like those 

 in Fig. 5, a few particles of Prussian 

 blue, and such particles of sand, 

 fibres, etc., as are always present in 

 any substance that has been more or 

 less exposed to dust. The poorer 

 the sample of tea is, the greater will 

 be the quantity of siftings, and the 

 more dirt, dust, fibres and coloring 

 matter are found ; there usually is, 

 according to my experience, a con- 

 siderable quantity of what appears to 

 be simply dried and powdered blue 



