370 ANNUAL OF SCIENTIFIC DISCOVERY. 



that some had been metamorphosed, as none but the arson ioally-fed larvte 

 had been admitted to the apartment. Experiments made to determine how 

 large a quantity of arsenic might be contained in flesh without rendering it 

 unfit for the food of these larvae were not very satisfactory, from the harden- 

 ing of the tissue by solutions of this substance preventing the deposition of 

 the eggs; eggs developed in such tissue bring forth living worms, Avhich in 

 his experiments died in six or eight hours. The adult flies perished in great 

 numbers, while depositing the eggs upon the poisoned flesh. Jaeger (quoted 

 by Orfila, Toxicologie, i. 379) alludes to the fact that larvae of flies live a 

 little longer than the perfect insects when arsenious acid is introduced into 

 the digestive organs or applied to their external soft parts. Under favorable 

 moist conditions, the larvae lived three or four days, and were evidently 

 nearly ready to pass into the chrysalid state. Experiments with arsenic acid, 

 used however in too concentrated a state, also showed that there is a limit to 

 the amount of arsenic which these larvae can support. 



He was inclined to believe that they can eat with impunity any flesh into 

 which arsenic has been carried by vital processes, from the fact of their 

 being found upon the arsenicated liver, an organ capable of absorbing a very 

 large quantity of this poison; anatomical preparations, injected thoroughly 

 with arsenic acid, have been found completely riddled and alive with larvae. 



This matter is important to chemists occupied in judicial investigations, 

 who should not infer that a fly-blown organ can contain no arsenic; though, 

 if flies die almost immediately after alighting on a suspected substance, 

 arsenic is probably present, and should be specially sought for. These facts 

 are also interesting as showing the great differences which exist in animals 

 in their several conditions of metamorphosis, and as indicating the caution 

 with which the results of experiments on one species should be received as 

 applying to other species. The popular belief that a body, dead from the 

 effects of arsenic, must of necessity be preserved from decay for an indefinite 

 length of time, is unquestionably an error; in many cases of murder or 

 suicide, where a great amount of the poison is administered, portions of or 

 even the whole body may be preserved for a long time; but the few grains 

 which it is admitted are enough to cause death cannot preserve from decay 

 so large a mass as a human body. That a small, though fatal, close will 

 not prevent decomposition, is well known to all who have ever had poisoned 

 rats die in the Avails of their houses. 



Dr. Cabot made a statement respecting the ravages of the larva? of Dcr- 

 inestes and Anihreni in specimens of birds supposed to be sufficiently protected; 

 the former, he said, attack the skin, the latter the legs and bill. Specimens 

 dipped in a very strong solution of corrosive sublimate, and in a saturated 

 solution of arsenious acid in hot water, were attacked by these larvae; but 

 specimens dipped into a tincture of strychnine were not touched by them. 

 Of the first two poisons, arsenic is the best; in specimens preserved by the 

 latter the skin was not touched, the larvae boring in through the legs. 



Dr. C..T. Jackson, in relation to the preservation of animal tissues by 

 arsenic, mentioned a case in which the stomach, carefully washed, had at 

 first assumed a yellowish tint, becoming soft, with an odor of ammonia, but 

 none of sulphuretted hydrogen, then changing into a pasty mass of a custard 

 yellow, and finally of the magnificent red of the sulphuret of arsenic, the 

 sulphur having been obtained from the decomposition of the tissues. In 

 another case, where the amount of the poison was greater, the abdominal 

 organs were perfectly preserved, and the walls shrivelled. 



