128 THE AMERICAN MONTHLY [June, 



stained. Other stains can probably be used with success, but whatever 

 stain is used, it must usually be very weak if the clearing action is to be 

 simultaneous with the staining ; for instance, a solution of one-tenth 

 of one per cent, would be sufficient for a fly's head, while a one per 

 cent, solution would probably not be too strong for a leg or other like 

 part. 



Carbolic acid has the disadvantage of coloring on exposure to light. 

 The crystals of the acid color very slowly, more than a year having 

 elapsed in one instance before they changed to a light amber, and even 

 then some portions of the mass (an ounce bottle full) remained clear. 

 The acid dissolved in a very small portion of water turned dark very 

 quickly, that is in a few days. That dissolved in 95% alcohol has re- 

 mained a light amber color after three months' exposure to daylight and 

 direct sunlight, being clear and transparent, while the aqueous solution 

 is dark and almost translucent. 



A solution of red analine in carbolic acid liquefied with alcohol has 

 remained brilliant and clear for a like period. Carbolic acid liquefied 

 by benzole has changed but very little, much less than the alcohol so T 

 lution, after a month's exposure to daylight and direct sunlight. In 

 each instance the bottles holding the acid were corked. A combined 

 solution of picric acid and carmine in carbolic acid dissolved in acetic 

 acid has shown no perceptible change for several days. Pure creosote 

 does not color on exposure to the air, and may possibly present all the 

 advantages of carbolic acid with none of its disadvantages, but having 

 had no opportunity to investigate I cannot give any information on the 

 matter. 



If for any reason any part of an insect has been removed so that the 

 acid can readily enter the interior of the body it will, after clearing the 

 soft parts, begin to dissolve or destroy them, and if an object be left in 

 the acid for some weeks nothing but the chitine will remain. 



Although the properties of carbolic acid and creosote have been 

 known for years, little appears to have been done with them, and an 

 interesting, fascinating field of study and experiment is open to any one 

 who can devote the necessary time and labor. 



The Reddening of Codfish. 



By CHAS. W. SMILEY, 



WASHINGTON, D. C. 



As early as 1838 it was noticed that salted codfish sometimes turned 

 red. In France, at that time, it was considered not injurious, but even 

 preferable. Within a few years the allegation that red cod was poi- 

 sonous has led to a careful examination of the subject. 



Its Appearance. — Sometimes small rosy specks are found to show 

 themselves upon the fish and to spread rapidly, so as to cover it quickly 

 and give it a thoroughly reddish appearance. This redness is fre- 

 quently to be found only on the surface, and then may easily be scraped 

 off; but sometimes it penetrates into the fissures of the flesh, and even 

 into the muscles and tissues of the fish. Entire cargoes sometimes 

 become more or less reddened before the termination of the voyage, 

 where there is heat and moisture. But this redness, which springs up 



