METHOD OF EXTINGUIS HrNG FIRE, 103 



VII. 



Letter fromM. Van Marum toM. Berthollet. Containing 

 an Account of fame Experiments, fieiving the Method of exiin- 

 guijking violent Fires with very f mall Quantities of Water, by 

 Means of Portable Pumps, 

 SIR, 



HEN I had the pleafure to fee you, during my flay in Hiftory of an 

 Paris, in September laft, you informed me that my experi- exttaeuifhing 

 ments, made on a large fcale fome years ago, to fhew the prac- fire, 

 ticability of extinguishing very violent fires with an inconfi- 

 derable quantity of water, were entirely unknown in France. 

 You at the fame time requefted me to fend you an account of 

 the experiments to be read at the national inftitute, and in- 

 ferted in the Annates de Chemie, My compliance with your 

 requeft has been prevented till now by the want of time. The 

 circiimflances which gave rife to the experiments were the fol- 

 lowing : 



Nine years ago, Van Aken, a Swede, publifhed at Stock- Anti -incendiary 

 holm, Copenhagen, and Berlin, that he could very quickly ex- ^* ter oi Van 

 tinguifh large artificial fires with an inconliderable quantity of 

 a liquid which he called anti-incendiary, the competition of 

 which he had for fome time kept fecret. Having obferved in 

 the journals, that M. Van Aken had repeated his experiments 

 with much fuccefs in Berlin, before fome members of the aca- 

 demy of fciences, I wrote to the celebrated M. Klaproth, re- 

 queuing, if he knew the compofition of the anti-incendiary 

 liquid, he would communicate it to me ; intending to (hew, at 

 this place, the merit of the invention, by an experiment on a 

 large fcale. With this intention, as foon as I had received 

 M. Klaproth's communication, I caufed Van Aken's liquid to 

 be prepared under my immediate infpedtion. The compofi- its compofition, 

 tion was a folution of 40lb. of fulphate of iron, and 30lb. of ful- 

 phate of alumine, mixed with 20lb. of the red oxide of iron, 

 and 200lb. of clay. I then commenced a feries of compara- 

 tive experiments, by forming two combuftible mafles, alike in 

 all circumftances ; fetting them on fire, and extinguifliing one 

 of them with the liquid of Van Aken, and the other with com- 

 mon water, I was much furprifed to find, in feveral trials, that, 



by 



