354 PERIODS SECT, XXXVI. 2, 2. 



much that beer taken to breakfaft will difturb the digeflion of 

 thofe, who have been accuftomed to tea ; and tea taken at din- 

 ner will difagree with thofe, who have been accuftomed to beer. 

 Whence it happens, that thofe, who have weak ftomachs, will 

 be able to digeft more food, if they take their meals at regular 

 hours ; becaufe they have both the ftirnulus of the aliment they 

 take, and the periodical habit, to affift their digeftion. 



The periods of emptying the bladder are not only dependent 

 on the acrimony or diftention of the water in it, but are fre- 

 quently catenated with external cold applied to the fkin, as in 

 cold bathing, or warning the hands ; or with other habits of 

 life, as many are accuftomed to empty the bladder before going 

 to bed, or into the houfe after a journey, and this whether it be 

 full or not. 



Our times of refpiration are not only governed by the ftimu- 

 lus of the blood in the lungs, or our defire of frefh air, but alfo 

 by our attention to the hourly objects before us. Hence when 

 a perfon is earneftly contemplating an idea of grief, he forgets to 

 breathe, till the fenfation in his lungs becomes very urgent ; 

 and then a figh fucceeds for the purpofe of more forcibly pufh- 

 Ing forwards the blood, which is accumulated in the lungs. 



Our times of refpiration are alfo frequently governed in part 

 by our want of a fteady fupport for the aftions of our arms, 

 and hands, as in threading a needle, or hewing wood, or in 

 fwimming , when we are intent upon thefe obje&s, we breathe 

 at the intervals of the exertion of the peloral mufcles. 



2. The following natural animal actions are influenced by fo- 

 lar periods. The periods of fleep and of waking depend much 

 on the folar period, for we are inclined to fleep at a certain hour, 

 and to awake at a certain hour, whether we have had more or 

 lefs fatigue during the day, if within certain limits ; and are li- 

 able to wake at a certain hour, whether we went to bed earlier 

 or later,within certain limits. Hence it appears, that thofe who 

 complain of want of fleep, will be liable to fleep better or longer 

 if they accuftoni themfelves to go to reft, and to rife at certain 

 hours. 



The periods of evacuating the bowels are generally connected 

 with fome part of the folar day, as well as with the acrimony or 

 diftention occafioned by the feces. Hence one method of cor- 

 reUng coftivenefs is by endeavouring to eftablifh a habit of 

 evacuation at a certain hour of the day, as recommended by Mr. 

 Locke, which may be accomplifhed by ufing daily voluntary ef- 

 forts at thofe times, joined with the ufual ftimulus of the mate- 

 rial to be evacuated. 



j. The following natural animal aftions are connefted with 



lunar 



