246 ANNUAL OF SCIENTIFIC DISCOVERY. 



fast: 3, after a brisk walk: and 4, after severe exertion. The 

 contents are then successively allowed to enter an exhausted brass 

 cylinder, the ends of which are stopped air-tight by plates of 

 rock-salt. Through this cylinder the radiation from a flame of car- 

 bonic oxyd gas is passing. Immediately the breath, which has been 

 deprived of its moisture, fills the cylinder, more than half the heat 

 from the flame is absorbed, and this entirely by the small quantity of 

 carbonic acid present in the expired air. The amount of heat inter- 

 cepted by the breath is, in each case accurately measured by means 

 of a delicate ihermomultiplier. The percentage of carbonic acid 

 contained in the different specimens of breath is found by calculation 

 and subsequent experiments, and is then compared with a chemical 

 analysis of each specimen. 



The close agreement between the methods of analysis is shown by 

 the following numbers : 



By physical analysis. By chemical analysis. 



Bag 1 4-00 .... 4-31 



Bag 2 4-66 .... 4*56 



Bag 3 5-33 .... 5*22 



These numbers indicate the percentage of carbonic acid in breath, 

 and show that the least amount of that gas was exhaled before breakfast. 



Many other different samples of breath have been examined by Mr. 

 Barrett ; the results he has obtained prove the great delicacy of the 

 new method of analysis in detecting small quantities of carbonic acid, 

 or in discovering variations in the amount of this gas in the atmosphere 

 or in the human breath. For this purpose its application in hospitals 

 has already been suggested by eminent men. 



Control of Diseaseby Sanitary Agencies. At a recent meeting of 

 the Social Science Congress, Dr. Lankester, in a paper on public 

 health, observed that " disease and death were most expensive things 

 to society, and when the death-rate rose above 30 in 1,000, that was a 

 death-rate which could be controlled by human agencv. This had 



v c^ tt 



been done in some large towns by proper attention to ventilation and 

 drainage, and thus great benefits had been conferred upon all." 



Animal Charcoal in Vegetable Poisoning. It is well known that the 

 infusion of coffee, tannin, camphor, vinegar, acetate of lead, fatty 

 oils, white of eggs, &c. have been proposed in succession as anti- 

 dotes to plants, or their alkaloids, belonging to the family of the papa- 

 veraceif , and the solanaceas. Now, Dr. Garrod prescribes animal char- 

 coal, which, in small quantities, neutralizes, or entirely destroys, the 

 action upon the economy of the solutions of belladonna, of stramo- 

 nium, and of hyoscyamus, provided that the antidote is administered 

 before they are absorbed. Dr. Garrod cites, in the Bulletin de The- 

 nrjieiitiqiie for 18;">8, two cases where patients had taken, by mistake, 

 one 60 centigrammes the other 10 grammes of belladonna, and were 

 immediately cured by the use of animal charcoal. Again, he admin- 

 istered to a dog a dose of aconite, which killed him promptly, while 

 another dog of the same size, which had taken four times as much 

 aconite, but mixed with animal charcoal, presented no symptom of 

 poisoning. M. Garrod has remarked that animal charcoal, purified or 

 not, acts in the same manner, and that vegetable charcoal, on the con- 



