Chemical Proccfs of Fita/iiy. 36 1 



TiErv'es appears to explain the effe£l of the fecretion of tlie feminal liquor on the blood. It 

 is this alkali which, diftrlbuted throughout the fytlem, anfwers the purpofe of a ftimulus 

 beneficial to the animal fibre. By this adion I account for the ferocity of the ichthyophagi. 



My eldeil brother, who is very (kilful in the ftudy of anatomy, applied zinc and filver 

 to the mouch and the brain of a dead fifli ; It alTorded no motion. I poured oxygenated 

 muriatic acid on the nerves, and at that Indant the contra£lionS became very flrong. Mr. 

 Herz and feveral learned men of Berlin were prefent at thefe and many other experiments. 

 The heart of the fame fiih, which had entirely ceafed to palpitate, began to perform this 

 movement with regularity when I threw It into the oxygenated muriatic acid. The fame 

 experiment fucceeded very often with the hearts of frogs : when a heart is Immerfed in a 

 folution of pot-afii, It lofes Its Irritability for ever; fo that azote is not the fpccific ftimulus 

 of the heart. 



Mr. Pfaffj while employed In my experiments refpefting germination in the oxygenated 

 muriatic acid, has difcovered that frogs fuftbcated In the oxygenated muriatic acid gas 

 exhibit a very high degree of irritability after their death. I beg you will fix the attention 

 of Mr. Vauquelin on the aftion of fulphate of pot-afh upon the nerves. I have been afto- 

 iiifhed at every thing I beheld. Two legs cf frogs In a very lively flate were ftecped In 

 the folution of the fulphate of pot-afh. I tried them three or four minutes afterwartls 

 with the metals. The contraftions had Increafed In force, and were even convulfive. It ap- 

 peared that the three acidifiable bafes contained in the folution hydrogenc, azote, and ful- 

 phur, a£ted ftrongly on the oxygene conveyed by the arterial blood. This aftion revives 

 the procefs of vitality. After fourteen or fixteen minutes the whole thigh became of a 

 blackifli brown. All the oxygene of the blood was abforbed, aud the carburet of hydrogene 

 appeared In a difengaged ftate. The zinc and the filver are not then capable of exciting 

 the fnialleft motion. 



Yet It would be a great mlflake to conclude that all iiritability Is exhaufl;ed in this cafe. 

 I have feen the contradlions re-appear feveral times on refloring oxygene to the fibre by 

 means of a folution of the oxide of arfenic. The flame Is thus renewed which feemed 

 ready to expire. The oxide of arfenic produces a tetanus and perfeft infenfibllity if the 

 nerve remalnslong immerfed. It feems then that the too great quantity of oxygene abforbs 

 as It were the acidifiable bafes which fupport the chemical proccfs of vitality. I have 

 thrown the whole thigh Into the folution of pot-afli, and I obferved that galvanlfm after-' 

 wards had the power of exciting motion. 



You fee. Sir, what an immenfe number of experiments remain to be made on thefe ob- 

 jefls of vital chemiftry. It is enough that a method has been pointed out of meafuring 

 the degree of Irritability of the organic parts by means of galvanlfm. I fliall have the 

 honour to fend you my work on the nervous and mufcular fibre, and on the chemical pro- 

 ccfs of vitality. I coUecl fads, and mlftruft my own hypothetical ideas.' You will perceive 

 with me how miflakcn the notion Is that oxygene performs the principal part in this procefs. 

 My experiments prove that the Irritability or tone of the fibre depends only on the mutual 

 equilibrium between all the elements of the fibre, azote, hydrogenc, carbone, oxygene, 

 lulphur, phofpliorus, &c. The chemical combinations of phofphorus and of azote, for 

 example, appear to be in no rcfpccl lefs important than thofe of oxygene with the acidi- 

 f.ablc bafes. How much light may we not expciTb from tlic advances of yourfelf, Four- 

 croy, and Vauquelin on thefe objefts ! Von IIumboldt. 



Vol. I.— NoviiMBER r797. 3 A /DDiriON 



