Chemistry. 381 



per, relates to the property which arsenic possesses of preserving from de- 

 cay the bodies of those poisoned with it. This subject, hitherto almost 

 entirely neglected in this country, has been investigated by the medical 

 jurists of Germany, who have supplied Dr Christison with most of the 

 facts which he has mentioned. The antiseptic effects sometimes extend only 

 to the stomach and intestines, that is, to the parts directly in contact with 

 it; but in some instances the whole body is preserved. The stomach and 

 intestines of persons killed with arsenic have been found entire and firm 

 at the distance of five, six, and fourteen months, or even at two years, and 

 two years and a-half after death ; and in some of these instances the poison 

 itself was detected. It appears from some cases of poisoning which have 

 fallen under Dr Christison's own observation, that, owing to the preserva- 

 tive action of arsenic, morbid changes of the stomach may sometimes be 

 clearly distinguished at an interval of two, three, or four weeks after death. 



18. MM. Delarive and Marcet on the specific heat of the Gases. — These 

 able young chemists have found that the specific heat of the gases submit- 

 ted to the same pressure is like their dilatability, always the same. M. 

 Gay Lussac had been led to another result, but this was owing to the appa- 

 ratus he employed. 



19. Phosphate of Magnesia more soluble in cold than in hot water. -^ 

 Philosophical Magazine and Annals for July. — Mr Thomas Graham has 

 observed that the phosphate of magnesia, like the hydrate of lime and 

 sulphate of soda, is more soluble in cold than in hot water. A solution 

 of this salt made with cold water was gradually heated by immersion 

 in the water-bath. Before the bath had reached the temperature of 120° 

 the solution became turbid, and it assumed more and more of a milky 

 appearance as the heat increased, till the temperature settled at 212'' 

 F., when a cloudy precipitate slowly subsided, and the supernatant 

 liquid became nearly transparent. The precipitate was found not to 

 differ in its sensible properties from phosphate of magnesia deprived of 

 its water of crystallization. According to the experiments of Mr Graham 

 one grain of the anhydrous phosphate of magnesia requires for solution 7i% 

 grains of water at 45° F. and lUl grains of boiling water. 



20. Liquid Phosphorus at 40° of Fahrenheit. — We have been favoured 

 with the following notice on this subject, by Mr T. Clark of Glasgow. 

 Though not unknown, I believe it is not generally known that a solution of 

 phosphorus in ether, essential oils, or the like, readily afibrds crystals by slow 

 evaporation. I noticed these for the first time last winter. For the purpose 

 of examination, I had put some of them into an evaporating dish with a little 

 water over them. In the evening, during a hurried visit to my laboratory, 

 I unwittingly filled this dish with boiling water, not observing the crystals I 

 had left in it. The night was a very cold one, and there was no fire in my 

 laboratory. Next morning I was surprised to see oil-like drops at the bot- 



