168 THE POPULAR SCIENCE MONTHLY. 



a somewhat populous country conducting its exchanges almost ex- 

 clusively by means of a monometallic, silver currency ; no other form 

 of money, with the exception of a small copper coinage, being practi- 

 cally used or recognized. The results were most instructive. Thus, 

 if one proposed to trade, even to a retail extent, or go on a journey, 

 a bag of coin had to be carried. If it were proposed to pay out a hun- 

 dred dollars, the weight of the bag would be five and a half pounds ; 

 if two hundred dollars, eleven pounds ; if five hundred, twenty-seven 

 pounds. Where collections or payments were to be large, and the dis- 

 tance to be traversed considerable, regular organizations of armed 

 men, and suitably equipped animals known as " conductas" were 

 permanently maintained ; and severe and bloody fights with bandits 

 were of common occurrence. At the great cotton-mill at Queretaro, 

 as already noted, the organization of a " conducta " men, arms, and 

 horses for making collections, was as much an essential of the busi- 

 ness as the looms and the spindles. " It was obviously impossible to 

 carry even a moderate amount of such money with any concealment, 

 or to carry it at all with any comfort ; and the unavoidable exhibition 

 of it, held in laps, chinking in trunks or boxes, standing in bags, and 

 poured out in streams at the banks and commercial houses, was one of 

 the features of life in Mexico," and undoubtedly constituted a stand- 

 ing temptation for robbery. Within a comparatively recent time, how- 

 ever, a national bank and banks of foreign incorporators have been 

 established in Mexico, and authorized to issue notes, on what appears 

 to be very inefficient security. The Mexican National Bank is under- 

 stood to be authorized to issue $60,000,000 notes upon a capital of 

 $20,000,000, which notes are legal tender from individuals to the 

 Government, but not from the Government to individuals, or between 

 individuals. The possibilities, if not probabilities, therefore, now are, 

 that a flood of depreciated paper will ultimately drive silver out of 

 circulation in Mexico. 







WHAT MAT ANIMALS BE TAUGHT? 



By M. J. DELBCEUF. 



" 1 1 iHERE exists in animals," says Malebranche, "neither mind nor 

 -L soul as we commonly understand the terms. They eat without 

 pleasure, they cry out without pain, they grow without knowing it, 

 they desire nothing, they know nothing, and, if they behave in a man- 

 ner betokening intelligence, it is because God, who made them, has, to 

 preserve them, formed their bodies in such a way that they avoid me- 

 chanically and without fear everything that is capable of destroying 

 them." Malebranche was more categorical than Descartes on the sub- 

 ject of soul in beasts. The latter had doubts on the matter. He 



