British Association for the Advancement of Science. 29 



fusely in the blood, and united with the oxygen inspired ; hence 

 they had carbonic acid. Dr. Carson had stated still further, that 

 sighing improved the circulation. He had paid considerable at- 

 tention to this, and he could not say that it improved it except in 

 one way, and that was, it occasionally gave freer play to the lungs. 

 They saw persons after being interested in any story almost sus- 

 pend their breath, or, in other words, forget to breathe ; and as 

 soon as the interest of the story terminated there was a very deep 

 inspiration, which relieved the blood in the chest. Bat he was 

 satisfied, that a series of inspirations did not invigorate the system. 

 Dr. Carson had also stated that the blood was not facilitated in its 

 return by inspiration. Experiments had frequently been perform- 

 ed which proved this. 



Dust in the Lungs. — Dr. Macintosh read a communication 

 from a medical student, on a disease of the lungs caused by tha 

 deposition of particles of dust. It would contribute, he observed, 

 towards the elucidation of that class of diseases affecting artisans, 

 which had, in a more systematic form, been treated by Mr. Thack- 

 rah. In the neighborhood of Edinburgh were many stone-quar- 

 ries, and the workers in which not unfrequently died from con- 

 sumption. A mason, a worker in the Craigleith-quarry, was ill j 

 he was bled and treated for a common cold, recovered, and re- 

 turned to his work. A short time afterwards he was again taken 

 ill, and, two years after the first attack, he died. During his ill- 

 ness percussion afforded a dull somid ; on the right side the steth- 

 oscope indicated no respiratory murmur; on the left a puerile 

 rale. After death, the lungs presented a black appearance ; 20 

 oz. of fluid were found in the right side, and 4 oz. in the left • 

 there was no membrane, the pleura being fibrous, which was rare. 

 Dr. Alison stated he had only seen this state once, being on the 

 pleura and cardiac portion of this kind of membrane ; both lungs 

 were completely studded with black tubercles, as if they were 

 melanotic, and cut like cartilage. Similar projections were on the 

 pleura, and the bronchial glands were long and hard, grating when 

 cut with the scalpel, owing to a cretaceous secretion like bone. 

 The analysis of this cretaceous matter showed it to be principally 

 the carbonate of lime. In the bronchial glands were carbonate 

 of lime, silica, and alumina. He directed particular attention to 

 this analysis, for Dr. William Gregory has published an account 

 of the Craigleith-quarry stone, and the analysis of this stone gave 



