156 PHILOSOPHICAL TRANSACTIONS. . [aNNO 1674. 



me, who am well informed that there are two sorts of the Helmontian lauda- 

 num ; the one used by the elder Helmont, the other by his son. The former 

 was, as a great secret, communicated to me by an expert chemist, sent by a 

 German Prince to compliment Johannes Baptista Van Helmont, some of whose 

 manuscripts (one of which perished in the fire of London,) he procured, to- 

 gether with a way of making his laudanum; which, having received from him 

 ,14 or 15 years ago, I carefully prepared, and thought my labour so well recom- 

 pensed by the extraordinary operations it had, not so much in my hands, as 

 those of learned physicians and others, to whom I presented portions of it, 

 that I should have thought the chemist a benefactor to physic, if he would 

 have made public, or permitted me to publish the way of making so successful a 

 medicine. And though the access to my laboratory was so free to ingenious 

 men, who knew such a medicine to be preparing there, that some of them might 

 easily suppose themselves masters of the secret; yet my justice to the commu- 

 nicator, who made a great and deserved benefit of the laudanum, made me take 

 that care to conceal some circumstances, that men may easily be much more 

 confident than sure that they have the right way of making the medicine. 

 Which, because I durst not communicate, meeting two years ago with Baron 

 Van Helmont, son to the famous Johannes Baptista, I obtained from him, by 

 word of mouth, some directions about the laudanum he uses; which, though 

 he confessed, and I soon perceived, to be different from his father's, yet he 

 seemed to think it not inferior, and more easily made. But he having, for a 

 certain reason, imparted to me his process only by word of mouth; lest it should 

 slip out of my memory, I soon after committed it to writing, as the particulars 

 I gathered from him occurred to me; and at the next season caused the 

 medicine to be prepared in my laboratory, where the progress was often watched 

 in my absence by a very learned and industrious London doctor j who having at 

 my. request made many trials with it, and some in cases where other laudanums 

 had been found unavailable, both uses it, and commends it more than I could 

 expect from so wary and judicious a man. This medicine being somewhat more 

 cheap and easy to be made than the elder Helmont's, the experience of its effi- 

 cacy made me desire of the younger a permission to communicate it for the 

 public good, and to prevent those spurious receipts that go about of the Hel- 



writings, too numerous for insertion here, is given in the 2d vol. of Haller's Bib. Med. Practica.— 

 His son Francis Mercurius Van Helmont, was not less remarkable for eccentricity than his father. 

 Besides several medical Tracts, he wrote a curious book entitled Alphabeti vere naturalis hebraici 

 delineatio, wherein he attempts to prove that the shape of the organs concerned in speech is corres- 

 pondent to the iigvire of the Hebrew letters. 



