ICE-MAKING AND MACHINE REFRIGERATION. 19 



St. Bernard still complained that monks had too much to do with 

 medicine ; and a few years later we have decretals like those of 

 Pope Alexander III forbidding monks to study or practice it. 

 In the beginning of the next century Innocent III, in the Council 

 of the Lateran, forbade surgical operations to be practiced by 

 priests, deacons, and sub-deacons ; some years later Honorius III 

 reiterated this decree and extended it. In 1243 the Dominican 

 Order forbade medical treatises to be brought into their monas- 

 teries. Five years later the Council of Le Mans forbade surgery 

 to monks, on the ground that " the Church abhors the shedding 

 of blood," and many other councils did the same. At the end of 

 that century Boniface VIII interdicted dissections as sacrilege.* 







ICE-MAKING AND MACHINE REFRIGERATION. 

 Bt feedeeik a. feenald. 



THE manufacture of ice now bids fair to become a regular 

 industry in temperate as well as in tropical climates. Pio- 

 neer work in this field was done more than sixty years ago, but it 

 is only within the last ten years that the groping attempts of the 

 early inventors have developed into processes sufficiently econom- 

 ical to make the artificial production of ice a commercial success. 

 Artificial ice has been made in tropical countries and in our 

 Southern cities for many years, but the industry has been greatly 

 extended in this country by the two successive mild winters of 

 1888-'89 and 1889-90. It has now gained a foothold even in our 

 Northern States, while in the South comparatively small towns 

 have their ice factories. 



The scientific fact on which the making of artificial ice de- 

 pends is that when a liquid evaporates it uses up a great deal of 

 heat, which it draws from anything that happens to be around it. 

 If a can of water is at hand, its temperature is reduced, and if 

 the action goes far enough the water will be frozen. This cooling 

 action can be felt by pouring a little ether or alcohol upon the 

 hand. The liquid evaporates rapidly, and the loss of the heat 

 which it takes up cools the hand very perceptibly. If a bottle 



* For exact statements as to these decrees of the highest Church and monastic authori- 

 ties against medicine and surgery, see Sprengel, Baas, Geschichte der Medicin, p. 204, and 

 elsewhere ; also, Buckle, Posthumous Works, vol. ii, p. 567. For a long list of Church 

 dignitaries who practiced a semi-theological medicine in the middle ages, see Baas, pp. 

 204, 205. For Bertrarius, Hildegarde, and others mentioned, see also Sprengel and other 

 historians of medicine. For clandestine study and practice of medicine by sundry ecclesi- 

 astics in spite of the prohibitions by the Church, see Von Raumer, Hohenstaufen, vol. vi, 

 p. 438. 



