666 PHILOSOVHICAL TRANSACTIONS. [aNNO 1780. 



began. Experiment is the only guide which we have to conduct us in our re- 

 searches: experiment is indeed a secure way of avoiding error, but experiment 

 does not always lead us to the more remote truths, nor always guide us to the 

 knowledge of the secret arcana of nature, nor yet always conduct us whither we 

 have proposed to go. 



But though we know not how the Laurel-water operates, or, more properly 

 speaking, on what part that poison exerts its action, when it kills animals; we 

 know however, that it is quite innocent when applied immediately to the nerves, 

 and even to their medullary substance : and it is equally true, that all the expe- 

 riments above related clearly show, that the poison of the viper and the Ame- 

 rican poison are both harmless any how applied to the nerves; but that they are 

 both poisonous when introduced into the blood. These are facts which were 

 before unknown; they are truths now laid open; nor can they be brought into 

 doubt again by any one. These facts destroy all the systems that have been in- 

 vented by the writers on the action of those poisons; and from these facts we 

 ought to set out, to arrive at the knowledge of those poisons, and of the manner 

 in which they operate. 



Some light might probably have been thrown on the action of the poison of 

 the Lauro-Cerasus, by applying it to different parts of the brain of living animals; 

 but I reserve this experiment for a more convenient occasion than the present, 

 and till I shall have reduced the Laurel-water to the consistence of syrup. In 

 that state, the poison being rendered much more active, will probably offer new 

 and more important facts, and may perhaps give a clearer insight into its opera- 

 tion; as also enable us to judge on what parts of living animals it acts so as to 

 kill them. I shall also reserve for that time the trial of whether that poison acts 

 on the lymphatic vessels, or, to speak more properly, on the lymph itself. This 

 is a mere suspicion which I have lately taken up, and which my present circum- 

 stances do not permit me to examine at present. I am therefore forced to give 

 my experiments on this subject, in some measure, defective and unconnected. 



VIL* Experiments relating to a New Animal Acid.-^ By F. L. F. Crell, 

 M. D., Professor of Chemistry at Helmstadt. p. lOQ. An Abstract from 

 the Latin. 



Professor Segnerj; of Gottingen having by distillation extracted from beef suet 

 an acid liquor, which by combination with the vegetable fixed alkali, and with 



* This paper should have been inserted at p. 628 of this Abridgment, immediately before tlie Ac- 

 count of a Woman who had the Small-pox durinp; Pregnancy. 



-J- At first called acid of fat, but afterwards denominated sebacic acid. 



\ Diss- Inaug. de Acido Pinguedinis Animalis; praeside lo. A. Segnero. Respond. D. H. Knappe, 

 Gott. 1754. 



