146 THE AMERICAN MONTHLY [Aug 



vacuoles in the corpuscles, deformed red corpuscles, etc., 

 for parasitic elements. 



SCIENCE-GOSSIP. 



Reagents for the Microscopical Examination of Food. 

 — Van Bastellar finds the following- reagents useful for the 

 microscopic examination of foods : — [1] Chloral hydrate, 

 5 ; distilled water, 3. This is an excellent clearing- me- 

 dium, and shows the structure of various cells, such as 

 beet in chicory, and chicory in coffee, also renders detec- 

 tion of inorganic matter mixed with starches more rapid. 

 [2] Aniline, 1 ; acetic acid, 10. Gives a brig-ht yellow tint 

 with schlerenchyma and woody tissue, detects powdered 

 nut shells, olive stones, etc., in pepper. [3] Acetic acid, 

 1 ; water 2. Gives a violet tint with fragments of tissues of 

 Melampyrum seeds in flour. [4] Potassium iodide, 1 ; iodine, 

 1 ; water 50. Renders starch distinct by coloring- the 

 granules blue and therefore making- the size and shape 

 more evident for their identification. [6] Potash, 1 ; 

 water, 100. Causes certain g-rains of starch to swell, and 

 thus distinguishes them from others which are more 

 resistant. Also gives a reddish tint with tumeric and a 

 violet color to erg-oted particles in flour. [6] Methyl 

 violet. 1 ; water, 300. Stains starch granules. [7] Tinc- 

 ture of logwood [1 in 15], 4 ; sodium chloride, 1. Detects 

 presence of alum in bread, flour, etc. [8] Sulphuric acid, 

 1; water, 20. Gives effervesence in presence of car- 

 bonates or bicarbonates, thus detects such mixtures as 

 chalk in flour. Also gives a blood-red tint to ergoted flour. 

 [9] Eosine, 1 ; solution of ammonia, 10. Stains altered 

 yeast cells and bacilli. [10] Haematoxylin, 1 ; water, 25 ; 

 alcohol, 25 ; sodium chloride, 5. Resembles No. 7 in 

 action. [11] Solution of ferric chloride, 1; water, 5; 

 blackens acron tissues, also those of leguminous seeds. 

 Gives a greenish tint to powdered date stones and other 

 adulterants in pepper. [12] Copper sulphate, 1 ; water, 

 20 ; ammonia q. s. to give a clear blue solution. Gives a 

 dirty greenish blue with some foreign admixtures with 



