106 THE AMERICAN MONTHLY [May, 



The variety Truitt is decidedly the best cotton, because the strands 

 are not only of a uniform size, but they are also remarkably well 

 twisted. Allen's Long Staple is not so satisfactory. The twist is not 

 as good, and the strands are irregular in size — some l^eing quite small 

 and weak. The two cuts representing Sea Island varieties show infe- 

 rior grades of cotton, weak and a decided lack of proper twist. 



Each division on the scales represented in the cuts is equivalent to 

 about ^g-Vo ^^ ^" inch. 



Clieap Boxes for Slides. 



Bv HENRY SIIIxMER, 



MT. CAKROLL, ILL. 



W. p. Hamilton's slide box described in the January number reminds 

 me of a very nice arrangement. A box ready-made is more apt to be 

 used than one made on purpose. For instance, tlie ordinary cigar box 

 costing nothing. The flat ones are most suitable. They vary in size 

 somewhat, but the ordinary one is about 4^ by 8^ by 2 inches inside. 

 It can be filled with card-board trays like Hamilton's, or with wooden 

 ones made of cigar boxes. The bottoms and lids will make bottoms 

 for the trays, and the sides and ends sawed into narrow strips ^ or ^ 

 inch wide and tacked on with brads, will make the margins. Each 

 box will hold five travs. The bottom may be used instead of a tray by 

 tacking a marginal strip in each end. Each of such boxes will store 70 

 short German slides, which by all odds are preferable, or it will hold 

 4!^ to ^o of the 3-inch slides. If we make the trays of cardboard, as 

 per Hamilton, and a 3-inch holds 24, 2-inch holds 16 trays. Then 14 

 short slides to a tray gives room for 224 slides ; 9 3-inch sheets to a tray 

 gives 144 slides, or 7 to a tray will give 112 slides, and allow about 

 ^-inch margin on the sides and a little less on the ends. Such boxes 

 are peat, cheap, and convenient. The slides lay fiat. These boxes 

 can be numbered or otherwise labelled on the ends and stowed in book- 



Bolting Gauze. — Mr. Charles M. Vorce, of Cleveland, Ohio, writes 

 that he has '■ done no microscopical work lately that has any novelty 

 in it, unless it may be the measurement of an assortment of bolting 

 gauze and other goods used for sieves, to ascertain the average and 

 maximum sizes of the particles which pass through the same, and the 

 relation of such size to the rating of the goods, which is always by the 

 number of naeshes to the inch or centimeter. Bolting gauze of '200 

 meshes to the inch ' will not pass particles of approximately globular 

 form larger than about ji^^ inch, and the average size of the particles 

 passed will be considerably less, about j^q." 



Correction. — On p. 60 for Pticciiiia anetnories read Pi(cci)iia 

 anemones ; for animal read annual. 



