575 



quantity of food be given, it will probably disturb the system and give 

 inaccurate results. It is necessary to give a moderate dose, and in 

 the customary form. The effect of all agents is temporary, and that 

 of all kinds of food begins quickly and attains its maximum within 

 1 to 2| hours. If the maximum effect only be sought for, that period 

 will suffice for the inquiry ; but if the average or total influence be 

 desired, it will be necessary to continue the inquiry until the whole 

 period of increase and decrease, or vice versd, have passed over. In 

 either case the experiments must be made every few minutes, and be 

 regularly repeated. The maximum quantities are easily attainable, 

 but the true average or the total effect is scarcely if at all so, since it 

 is difficult or impossible to ascertain the precise period of the termi- 

 nation of the effect. Hence only one dose of the food can be given 

 on the same day, when great accuracy is desired. A second period 

 may be found at about 4| hours after the breakfast; but, although it 

 is next in value to the period before breakfast, it cannot be implicitly 

 relied upon, since no proof could be obtained that the vital functions 

 had subsided from the breakfast increase to their lowest point before 

 the inquiry began. All such experiments must be tested by morning 

 inquiries. Whenever there is a sense of craving for food, or any 

 disturbedfeeling, it is highly probable that the vital actions are varying, 

 apart from the influence of the food, and the inquiry should be ter- 

 minated. The addition of water to the food does not vary the results 

 connected with the respiration, except so far as it may enable the food 

 to enter the circulation quickly. If the solution of the food have 

 been imperfect, the subsequent ingestion of water alone will cause an 

 increase in the effect equal to that of taking more food. 



II. " On the Motions of Camphor on the Surface of Water." 

 By CHARLES TOMLINSON, Esq., Lecturer on Science, 

 King's College School, London. Communicated by Dr. 

 WILLIAM ALLEN MILLER, Treasurer and V.P.R.S. Re- 

 ceived January 15, 1862. 



(Abstract.) 



The object of this paper is to show that the phenomenon in ques- 

 tion is a much more general one than is commonly supposed ; that 



