32 o UTILITARIAN ZOOLOGY 



mon contagion,' writes Sir Kenelm Digby in 1660, 'men used 

 to carry about with them the powder of a toad, and sometimes a 

 living toad or spider shut up in a box, which draws the contagious 

 air which otherwise would infect the party'; and many other illus- 

 trations of their employment as preventive or remedies might be 

 given. The spider and the toad seem to have been each regarded 

 as most venomous creatures, and in many of the old remedies one 

 or other of them at will are recommended, either alternative being 

 regarded as equally efficacious; thus for whooping-cough, if one 

 cannot find a toad to thrust up the chimney, two spiders in a 

 walnut-shell will serve equally well." 



The physicians of former times were* particularly fond of ad- 

 ministering all sorts of animal extracts, some of them noisome 

 enough, and it is somewhat curious that of recent times large use 

 has been made of certain such extracts with beneficial result, 

 though it need hardly be said that our modern methods of pre- 

 paration are not on the old lines. Pepsin, for instance, a well- 

 known aid to gastric digestion, is prepared from the lining of the 

 pig's stomach, while pancreatin, which facilitates intestinal diges- 

 tion, is obtained from the pancreas of domestic animals. Disease 

 of the thyroid " gland " in the throat leads to serious mal-nutrition, 

 or even to cretinism, palliation if not cure of which can be 

 effected either by grafting a healthy piece of thyroid from an 

 animal into the patient, or by administering thyroid extract. 

 Several other preparations of the kind are also in use. Certain 

 specific germ-diseases can also be prevented or combated by 

 animal preparations, the most familiar instance being that of 

 vaccination as a safeguard against small-pox. Diphtheria is now 

 often cured by an extract (antitoxin) derived from horse's blood. 

 Different principles are involved in the uses of the extracts, &c., 

 mentioned, but details would here be out of place. 



Various kinds of animal fat are used in pharmacy in the pre- 

 paration of ointments, &c. They include mutton suet, hogs' lard, 

 spermaceti, and lanoline, the last being the natural grease of wool. 

 Gelatine is employed for making " gelatine lozenges" and various 

 jujubes, also as the adhesive medium for " court plaster". It is 

 obtained from bones, hides, horns, and hoofs by steaming. Isin- 

 glass (see p. 278) is a superior kind of gelatine. 



It should not be forgotten that the careful study of the 

 anatomy and physiology of lower animals has played a leading 



