USE OF METEOROLOGICAL OBSERVATIONS TO NAVIGATORS. 55 



we might find by these tables the general state of the at- 

 mosphere and water pertaining to it ; and thus ascertain its 

 influence on the mariners who traverse it, and the animals 

 that people it. 



In my meteorological labours, however, I had in view an 

 object still more essential, and more immediately useful to 

 seamen. Theory and experience, in fact, seem to unite to Chief cause of 

 prove, that the chief, if not the exclusive cause of scurvy is scurvy. 

 moisture, whether combined with heat, or with cold. This 

 opinion, which Mr. Kerauden has particularly unfolded in 

 his excellent dissertation on this subject, and which my own 

 disaster* confirmed, led me to consider it as a duty, to direct 

 my inquiries to this subject; and to pursue them with the 

 more care, as I had the advantage of being the first to tra- 

 verse the seas with an hygrometical instrument capable of 

 being compared with others, that of de Saussure, executed 

 by Richer. Besides, Mr. Halle, to whose instructions and 

 advice I am so much indebted, recommended observations 

 of this kind to me at my departure; and the desire of tes- 

 tifying my gratitude to him, at least by my zeal, was a 

 powerful motive with me to undertake them. 



Independant of my other meteorological researches, there- j,, , , 

 fore, I imposed on myself the task of making particular observations. 

 experiments on the comparative state of different parts of 

 our vessel. Every ten days, at noon and at midnight, I 

 went from the poop beneath the quarter deck and fore- 

 castle*, thence to the gunroom, and lastly tp the hold, where 

 I caused myself to be shut up for half an hour, to obtain 

 results more exact, and more accurately comparable. The 

 captain, who had requested me to communicate to him the 

 results, and transcribed them into his journal, always 

 afforded me, as I must candidly confess, every possible con- 

 'venience for this purpose; and in this respect, at least, he 

 was pleased to second my endeavours. 



My observations toward the close of October 1800 showed information 

 roe, that the matter of the vomitings of several persons at- derWed from 

 tacked with seasickness, and too much crowded in the gun- 

 room, had altered the air in a dangerous manner by its 



* Sous le gaWardst in the original ; though, from the table, I sup- 

 pose the author means the between- decks. C. 



decomposition 



