REPORT ON A MEMOIR. \Q\ 



at this negative refult with the two firtt metals, which are not 

 eafily oxidable, but zinc and iron promifed an inflammation* 

 becaufe they detonate by a blow. 



Brown oxide of copper, the refidue of the difiillation of Metallic oxide* 

 acetate of copper burnt without flame, with fparks refembling 

 thofe from gerbes d'artificc (a kind of firework called the wheat 

 fheaf.) 



Metallic fulphurets fucceeded pretty well, particularly the fulphurets, 

 fulphuret of tin or aurum mufivium, and the black fulphure of 

 mercury. The laft yields a very beautiful white flame. Am- 

 ber, fuccinic acid, bitumen, did not take fire, but the decre- 

 pitation was very considerable. 



Among the vegetable fubftances fome inflamed eafily, fuch Vegetables. 

 as the volatile oils, refin, turpentine, gum copal *, and gum 

 elemi, gum arabic, the duft of lycopodium, foap, camphor, 

 cotton, and fawduft. This laft article did not always fucceed, 

 but with the addition of a little fulphur it makes an excellent 

 powder of fufion, which from the facility of its inflammation 

 by a re-agent, may be ufeful to mineralogies. 



We tried ftarch, it inflamed with difficulty, but we fuc- 

 ceeded in making it burn. Ether takes fire very quickly. We 

 ©bferved that in this experiment as well as in thofe with cam- 

 phor and alcohol, very little of the fur-oxigenated muriate was 

 decompofed, and it did not burn, but was folely of fervice to 

 favour the inflammation. To afcertain that fad, we mixed 

 fulphur with the refidue of the experiment, the fulphuric match 

 produced a fecond eombuftion. 



We made a paite with the fur-oxigenated muriate and 

 honey; this mixture caught fire, fwelling up and emitting an 

 odour of boiling, fugar mixed with a very penetrating acid, 

 which one of us believed to be acetic acid. 



Chryfiallized benzoic acid diffufes a confiderable reddffli 

 flame; tartareous acid and acidule burn alfo very well; tar- 

 trite of potafh offers a beautiful whitifli flame; tartrite of foda 

 prefents neither inflammation nor light. Antimoniated tartrite 

 of pjtaih gives beautiful fparks without flame. 



Oxalic acid with the oxigenated muriate fparkles without 



* The gum refin, copal, ftill but little known, has been aflimi- 

 lattd by feme chemifts with amber. This experiment eftablimes a 

 very remarkable difference between thefe two iubfrances. 



inflammation. 





