On the different Forms of Breathing. 95 



seismal lines in these directions, and (2) by the greater prominence 

 of the sound in the south-east part of the disturbed area and of the 

 shock in the north-west part. 



After two or three seconds there appears (from the double charac- 

 ter of the shock) to have been a second and slighter slip, probably at a 

 short distance to the north-west of the former. 



History of the Charnwood Forest Fault. The greater part of the 

 displacement along the anticlinal fault seems to have taken place in 

 pre- Carboniferous times, leaving only a few hundred feet to be ac- 

 complished in subsequent periods.* Earthquakes in the Charnwood 

 district are now extremely rare. Between December 23, 1838, and 

 August 4, 1893, we have not one recorded.f The shocks of the pre- 

 sent century thus indicate at how slow a rate the fault is now grow- 

 ing. They also show that that growth has not yet ceased, and 

 enable us to form some conception of the vast interval of time over 

 which the life of a fault may extend. 



" On the Different Forms of Breathing." By WILLIAM MARCET, 

 M.D., F.R.S. Received June 12, Read June 21, 1894. 

 Revised September 7, 1894. 



I must beg leave at the outset to acknowledge the valuable aid of 

 my Assistant, Mr. R. B. Floris, F.C.S., in the present inquiry. An 

 investigation of this kind, necessitating much consideration, can only 

 be carried to a successful issue by arguments and discussions, and to 

 Mr. Floris much credit is due for the light these discussions have 

 shed on the inquiry ; I feel also indebted to him for the care- he has 

 bestowed on the numerous analyses he has made for me, and for the 

 accuracy with which his work has invariably been done. 



From a general view of the function of respiration it follows that 

 there are four fundamental forms of breathing ; their characters are 

 the following : 



1st. Normal breathing in the state of repose a regular succession 

 of the respiratory movements, involuntary, unattended with fatigue, 

 and leaving an approximately unchanged balance between the C0 2 in 

 store, in the blood, and the C0 2 expired. 



2nd. Forced breathing a voluntarily increased thoracic expansion, 

 brought about by the contraction of muscles differing more or less 

 from those in comn on use in respiration and attended with fatigue. 

 The expiration of carbonic acid is increased beyond the normal; 



* ' Quart. Journ. Geol. Soc./ vol. 34, 1878, p. 232. 



f W. Koper, ' A List of the more remarkable Earthquakes in G-reat Britain and 

 Ireland during the Christian Era ' (Lancaster, 1889), pp. 34 42. 



