Experiments on Fluids, &c. 37 



an inconvenience which those who wish to discharge wri- 

 ting from paper know very well how to profit by. This 

 circumstance, no doubt, induced M. Tarry to make some 

 new experiments in order to obtain an ink which should be 

 inalterable by chemical agents ; and he appears to us to have 

 succeeded in his object. 



ARTICLE IV. 



Discovery of an Ink ivkich resists the Action of chemical 

 yjgenis. 



The author describes his invention in the following words ; 



" Mv ink is founded upon principles diflcrent from those 

 of all others. It contains neither gall-nuts, -Brazil wood, 

 or Campeachy, gum, nor any preparation of iron: it is 

 purely vegetable, resists the aclion of the most powerful 

 veoetables, the most highly concentrated alkaline solutions, 

 and, finally, all the solvents. 



•' The nitric acid acts very feebly upon the writinsj per- 

 formed with this ink. The oxymuriatic acid makes it as- 

 sume the colour of pigeons' dung. After the action of this 

 last acid, the caustic alkaline solutions reduce it to the 

 colour of carburet of iron: the characters of the writing 

 nevertheless remain without alteration, and it cannot pass 

 through these different states except afier long macerations. 

 The principles of which it is composed render it incor- 

 ruptible, and it can retain its properties many years." 



The results which we obtained, coincided entirely with 

 those of the author, and we have no hesitation in saving, 

 that his is the best we have ever seen of the kind which is 

 called indelible ink. It is liable, however, to deposit a 

 sediment, a disadvantage which we think might be removed 

 by M. Tarry after a few more experiments. We have 

 tried to discharge it with all the known chemical agents, 

 but without effect; and we think the inventor deserves the 

 thanks of the Instituic, and of the community at large. 



VII. Experiments to prove that Fhnd<; pass directly from the 

 Stomach to the Circulation of the Blood, and J'rotn thtnce 

 into the Celli of the Spleen, the Gall Bladder, and Urinary 

 Bladder, ivitkojU going through the Thoracic Duct. By 

 EviiRARD lloML, Esq. F.R.S." 



XJ.AVING on a former occasion laid before the Society some 

 experiments, to prove that fluids pass directly from the car- 



* Frmn the Philosophical Transactions for 1811, Part I. 



C 3 diac 



