On the Nutrition of Muscular and Pulmonary Tissues. 443 



in the violet, coupled with the fact now presented by me, that 

 the heat of the upper half of the spectrum is equal to that of 

 the lower half, it follows that the true distribution of heat 

 throughout the spaces of the spectrum is equal. In con- 

 sequence of the equal velocity of ether- waves, they will, on com- 

 plete extinction by a receiving surface, generate equal quantities 

 of heat, no matter what their length may be, provided that 

 their extinction take place without producing any chemical 

 eftect. 



3rd. That it is incorrect to restrict to the upper portion of 

 the spectrum the property of producing chemical changes. 

 Such changes may be produced by waves of any refrangibility. 



4th. That every chemical effect observed in the spectrum is 

 in consequence of the absorption of specific radiations, the ab- 

 sorbed or acting radiation being determined by the properties 

 of the substance undergoing change. 



5th. That the figure so generally employed in works on 

 actino-chemistry to indicate the distribution of heat, light, and 

 actinism in the spectrum, serves only to mislead. Its heat- 

 curve is determined by the action of the prism, not by the pro- 

 perties of calorific radiations ; its actinic curve does not repre- 

 sent any special peculiarities of the spectrum, but the habitudes 

 of certam compounds of silver. 



LIII. On the Nutrition of Muscular and Pulmonary' Tissues in 

 Health and when affected with disease from Phthisis. By 

 William Marcet, M,D., F.R.S. 



[Concluded from p. 365.] 



Part II. 



On the Constitution and Nutrition of Pulmonary Tissue in Health. 



I HAD been prepared to find that the mode of nutrition of 

 muscular tissue equally applied to pulmonary tissue ; but the 

 result of the inquiry showed that there is a difference between 

 the two processes. The investigation was carried on in the same 

 way as in the case of muscular tissue. 



Three samples of pulmonary tissue from three different oxen, 

 submitted to analysis, gave the following results : — 



