Joseph Henry's First Lecture for his Natural Philosophy Course

Usage Conditions Apply
The Smithsonian Institution Archives welcomes personal and educational use of its collections unless otherwise noted. For commercial uses, please contact
Request permissionsDownload image Print


First lecture of Joseph Henry, then a professor at Princeton University and later first Secretary of the Smithsonian Institution, for his natural philosophy, or physics, course.


Princeton University


Historic Images of the Smithsonian

Contained within

Smithsonian Institution Archives, Record Unit 7001, Box 18, Folder: 1 - Introductory Remarks and First Lecture

Contact information

Institutional History Division, Smithsonian Archives, 600 Maryland Avenue, SW, Washington, D.C. 20024-2520,


c. 1840s

Restrictions & Rights

No restrictions


  • Lectures and lecturing
  • Secretaries
  • Physics
  • Teaching


  • Document
  • Paper

ID Number

SIA2012-3188 and SIA2012-3189 and SIA2012-3190 and SIA2012-3191 and SIA2012-3192

Physical description

Number of Images: 5; Color: Color; Size: 5w x 7 3/4h; Type of Image: Document; Medium: Paper

Full Record

View Full Record

Lecture [[underlined]] 1st [[/underlined]] 1. Philosophy is the knowledge of the general laws which regulate the [[underlined]] phenomina [[/underlined]] of nature whether in the material or intellectual world. = The word phenomina the plural of phenominon which occurs frequently in the sciences indicates the collectd appearance of any class of facts. The term law of Nature expresses the [[relation?]] which exists among these facts [[vertical in margin]] see Playton's outline [[/margin]] 2 = Philosophy is divided into two great branches corresponding to the two great classes of substances material and immaterial. The material world is the province of [[strikethrough]] the [[/strikethrough]] Natural Philosophy the properties and actions of the bodies which compose the universe and the objects of its investigation = Natural philosophy is however now restricted to the knowledge
of the general properties of bodies or to those properties which belong to all matter and the laws of the mechanical actions of bodies on each other. = Chemistry investigates the [[strikethrough]] [[?]] [[/strikethrough]] peculiar properties of bodies & the perminent changes which they effect on each other - = The distinction of the two sciences will however be best learned by studying each [[insertion]] of these [[/insertion]] branch of knowledge but then the definition is useless - = In some cases a principle may belong to bothe these sciences. Thus heat when it expans a body but produces no perminent change [[strikethrough]] [[?]] [[/strikthrough]] in its structure belongs to Natural philos. but when it burns a body the process is a chemical one- There are three ways principally by which man has arrived at [[strikethrough]] [[?]] [/strikethrough]] [[insertion]] his present [[/insertion]] knowledge of the laws of nature. 1st by observation - by watching the operations of nature as they take place around us. 2nd by experiment or by placing matter in some untried position [[end page]] [[start page]] or connection with other matter and of noting the result. In this respect experiment is only an other method of observation by which we hasten the process. Or according to Bacon it is a method of asking nature a question which she sometimes answers directly in the negative or the affirmative but sometimes very ambiguously. 3rd By reflecting on a number of facts which we have collected by the two former methods and by a method of reasoning called induction arriving at a general law & this law being applied in a converse manner is made to point out new facts which may be again verified by experiment - This is the Baconian method of studying nature. The process arising from particular [[insertion]] facts [[/insertion]] to general laws or axioms is called [[underlined]] Induction [[/underlined]]. The descending from General laws to particular facts is called [[underlined]] Deduction [[/underlined]] Simple & sure as this methods are investigating the laws of the operations of nature they were not used by the [[end page]]
to any extent & hence the little progress they made comparatively in the study of natural phenomina. Instead of collecting many facts and deducing general principles from them they reasoned over a few facts according to the rules of logic and thus came in most cases to the most absurd conclusions. = The ancients were not in the habit of using the experimental method which is by far the most effecatious method of collecting facts in reference to the operations of nature they did not however entirely neglect observation particularly in astronomy hence they made some considerable advances in that science. = Branches of science which do not furnish facilities for experiment or allow of but rare observation make but slow advances Example The Shooting Stars. = All investigation of the phenomina of nature proceed on one supposition viz that the laws of nature are immutable [[end page]] [[start page]] therefore a particle of matter under the same circumstances will act on an other particle precisely in the same manner how many times [[should?]] the two be placed in the same condition with regard to each other. This principle could not be [[inferred?]] [[underlined]] [[AbInitio?]] [[/underlined]] but is confirmed by all experience. It was not recognized by the ancients & hence they had two kinds of matter the corruptible & the incorruptible. = We are said to explain a phenomenon when we refer it to a more general fact. We say that one phenominon is the cause of an other when [[strikethrough]] [[?]] [[/strikethrough]] [[one causes]] the existence of the one to depend one in some way on the other. We have however no [[intimate?]] knowledge of cause & effect [See [[Abercrombie?]] ] When we assume or immagine a fact for the purpose of [[explaining?]] or connecting a number of facts the fact so assumed is called an Hypothesis.
If the number of facts or appearances explained by an Hypothesis be very great or if it be founded on known facts. It is called a [[underlined]] Theory [[/underlined]] Theories are often used only as convenient expressions for general laws - or [[insertion]] as [[/insertion]] sytems of experimental classification of phenomina and in this way are of the utmost importance. A body is a seperate collection of matter included in definite boundaries - [[end page]] [[start page]] The collection of phenomina which is generally collected under the study of Natural philosophy may be classfied under the following distinct heads - 1 [[underlined]] Somatology [[/underlined]] which exposition of the general properties of [[strikethrough]] matter [[/strikethrough]] bodes considered individually and necessary to the seperate existance- [[underlined]] or better [[/underlined]] Which comprehends the knowledge of the external & general properties of bodies considered individually 2 - Statics or the phenomina of ^ [[insertion]] solid [[/insertion]] bodes in a state of rest [[strikethrough]] [[where?]] [[/strikethrough]] or equilibrium when acted upon by two or more forces. 3 = Dynamics or the phenomina of solid bodes in motion 4 = Hydrostatics or the [[equilium?]] of Liquids [[line]] 5 = Hydrodynamics or the phenomina of Liquids in motion the old name is Hydraulics. 6 [[underlined]] Pneumatics [[/underlined]] or states & dynamics applied to air and gasses -
[[1?]] 6 The phenomina of Light including optics = 7 The phenomena of Heat = 8 of Electricity = 9 of Galvanics = 10 and of Magnetism - 12 = sound When statics + dynamics are applied to the heavenly bodies they constitute astronomy = When to the construction of machines etc they constitute [[underline]] Practical Mechanics [[/underline]] [[Muses?]] of Natural Phil [Leslie 1 It improves and elevates the mind by unfolding the magnificence the order and the beauty [[strikeout]]of[[/strikeout]] manifested in the construction of the material universe 2 It offers the [[insertion]] most [[/insertion]] striking proofs of the benefesence of the wisdom and the power of the Creator 3 It gives man a power over the opperations of nature which enables him although naturally one of the weakest and most defenceless of animals to become the ruler of the world.