156 



Alluding to former observations for the purpose of determining 

 the dip in London, the author observes that, independent of any im- 

 perfection in the instruments, they were made in houses in close 

 built parts of the metropolis, and, therefore, all subject to the in- 

 fluence of local attraction ; and, moreover, that the correction found 

 by observing the difference of the dip on the outside of the house 

 cannot be regarded as an effectual remedy, inasmuch as the needle 

 may still have been attracted by iron in the adjoining houses, or in 

 the neighbourhood. It is, indeed, only requisite to try needles in 

 different situations in a city, to be convinced how little dependence 

 should be placed in the accuracy of such results : the author thinks 

 that it is rather owing to this cause than to instrumental error, that 

 the dip at the Apartments of the Royal Society is stated in the Phi- 

 losophical Transactions for the present year to be 71 06'. To avoid 

 this source of error, Captain Sabine conducted the observations which 

 form the subject of this lecture in the nursery-ground in the Regent's 

 Park, a situation which he regards in all respects eligible, and far 

 removed from the influence of iron. 



Some Positions respecting the Influence of the Voltaic Battery in ob- 

 viating the Effects of the Division of the Eighth Pair of Nerves. 

 Drawn up by A. P. Wilson Philip, M.D. F.R.S. Edinb. Commu- 

 nicated by B. C. Brodie, Esq. F.R.S. Read July 5, 1 821 . [Phil. 

 Trans. 1822, p. 22.] 



The positions established by Dr. Philip, to the satisfaction of Mr. 

 Brodie, are detailed in this paper in the following order. 



First. When the nerves are divided and the ends not displaced, if 

 the animal live some hours, food swallowed before the operation is 

 much digested ; but if the ends of the nerves be turned from each 

 other, no perfectly digested food is, under the same circumstances, 

 found in the stomach, nor does digestion go on though the animal 

 live ; but galvanism applied to the nerves occasions a degree of di- 

 gestion in the food contained in the stomach, and when galvanized 

 the animal does not suffer from dyspnoea. When the nerves are 

 simply divided, and the animal lives for six hours, the lungs become 

 congested ; but they appear healthy when galvanism has before been 

 sent through the lower portion of the divided nerves. 



On some Alvine Concretions found in the Colon of a young Man in 

 Lancashire, after Death. By J. G. Children, Esq. F.R.S. 8(C. 8(C. 

 Communicated by the Society for Promoting Animal Chemistry. 

 Read December 13, 1821. [Phil. Trans. 1822, p. 24.] 



After detailing the above, and adverting to two other cases of in- 

 testinal concretions, Mr. Children describes the appearance and 

 composition of the calculi. The nucleus of each was a plumstone 

 enveloped in a compact coating of phosphate of lime and ammoniaco- 

 magnesian phosphate, and of a fibrous substance alternating in lay- 



