^.6 THE POPULAR SCIENCE MONTHLY. 



tor himself, with his regular treatise " On Corpulence in Relation to 

 Disease." Dr. Harvey's book is an excellent summary of the subject, 

 and has the weight of professional and scientific authority ; the pres- 

 ent article is mainly condensed from his pages : 



The manner in which fat is distributed over the body is now generally 

 understood to be by the texture of the cellular membrane. Formerly it 

 was thought to adhere in clusters to the parts where it was found a 

 mistake that has been corrected by the study of minute anatomy. The 

 cellular tissue, as its name implies, is made up of great numbers of 

 minute cells, which communicate with each other, and which are 

 formed by the interlacings of fine, soft, colorless, elastic threads, inter- 

 mixed with delicate films or laminae, the tissue presenting, when free 

 from fat, a white, fleecy aspect. This tissue is found everywhere 

 undei-neath the skin ; the serous and mucous membranes are attached 

 by it to subjacent parts ; it lies between the muscles, and also among 

 their fibres, surrounds the blood-vessels, and is generally distributed 

 throughout the body. In certain situations, as around the large blood- 

 vessels and nerves, in the omentum and mesentery, about the joints, 

 and especially under the skin, the cells enclose what are known as 

 adipose vesicles, minute spherical pouches, filled with fat or oil ; and, 

 when these are present in notable quantity, the structure takes the 

 name of adipose tissue. As thus deposited, the fat appeai-s merely to 

 be held in store, as it remains quite distinct in form and situation from 

 other parts of the animal frame. It, however, enters largely into the 

 composition of nerve-substance, where it becomes an essential part of a 

 highly-organized tissue. 



The development of fatty tissue varies considerably at different 

 ages, and in the two sexes. In children and in females, especially in 

 early age, the principal seat of the fatty deposit is in the cellular tis- 

 sue, immediately under the skin. During adolescence, the fat has a 

 tendency to disappear from this situation ; but, about middle age, fre- 

 quently becomes again deposited, not only in the subcutaneous tissues, 

 but also in the neighborhood of certain internal viscera. The quality 

 of the fat also varies, both with the age and with the part in which 

 it is deposited. It is firmer and higher colored in old persons than 

 in young ones ; and is more condensed and solid in parts liable to 

 compression, than in the omentum, or about the heart, stomach, and 

 intestines. 



A moderate amount of fat is a sign of good health, and physiolo- 

 gists generally allow that it ought to form about the twentieth part of 

 the weight of a man, and the sixteenth of a woman. Independently 

 of its importance as a non-conducting substance in impeding the too 

 rapid escape of animal heat, fat may also be regarded as a store of 

 material to compensate for waste of tissue, under sickness, or other 

 circumstances, entailing temporary abstinence from food. But when fat 

 accumulates to the extent of interfering with important functions, and 



