40 " THE LEAVES OF THE TREE W6T6 FOE THE HEALING OF THE NATIONS." 



badly swindled by conscienceless contractors. Contracts have been vio- 

 lated, specifications ignored, and money collected for work that has not 

 been done. The sewer commission has found numerous instances in 

 which every rule of good work has been violated. Rotten brick has been 

 used, mortar has been made of mud, and the trenches have been dug so 

 that the sewer in the center of a block has been higher than at either 

 end. This is something worse than swindling. It is a crime that in- 

 eludes the deliberate poisoning of the people who live along the line of 

 the rotten work. This form of rascality is deserving of severer punish, 

 ment than falls to the lot of the common thief or pickpocket. If the 

 man who breaks into a house to steal a loaf of bread gets a dozen years 

 in prison, the rascal who cheats the citizens and the city by laying a rot- 

 ten sewer deserves a lifetime behind the walls of Folsom.") 



" It was discovered that the generation of these swarms can be prevented in a 

 very simple way. That if the bullion is kept for some time at boiling temperature 

 and then sealed at once to prevent the access of air, it will remain clear for days, 

 tor weeks, for indefinite periods, and show no trace of living forms on microscopi- 

 cal examination. The sole difference in the treatment of the fluid in the two cases 

 has been the exclusion of air. And so men came to look in the air for the source 

 of the changes so long misunderstood. Then slowly, step by step, came the name 

 cocci, from the Greek word meaning a berry or pill. Others look like short rods, 

 and hence get the name bacteria, from the Greek word meaning a rod. Still 

 others of a similar shape, hut a little longer, are called bacilli, from the Latin 

 word meaning a staff. And, lastly, there are forms called spirilli, because they 

 look like long, twisted spirals. Though science gives these distinctive names to 

 different forms, yet popular usage designates all germs as bacteria, regardless of 

 their shape. In size, though all are visible to the naked eye, there is nevertheless 

 great variation among them. Some of the cocci are but 1-20,000 of an inch in 

 diameter, so that 20,000 of them together in a heap would occupy only one cubic 

 inch of space. Some of the spirilli, on the other hand, attain a length of 1-300 

 of an inch, but with germs as with men, the stature of the individual bears no 

 relation to its influence or to its possibilities. 



" In structure all these living germs are bnt simple vegetable cells. Imagine a 

 minute speck of matter of jelly-like consistency, the surface a little more firm and 

 dense than the center. Such is the living cell, the last step in the subdivision of 

 all living structures. The anatomist, with his knife, can dissect the animal body 

 and reveal the different tissues of what it is composed the muscles, the bones, the 

 arteries and the nerves and the connecting strands that binds the partis together. 

 But with his microscope he goes on far beyond that point and learns that each 

 muscle, bone and nerve is itself made up of multitudes of individual cells, diff- 

 ering vastly in shape and size according to the tissue in which they are found, but 

 all essentially the same in structure. So the botanist can take apart the plant and 

 show its various tissues, but each of those tissues, beneath the microscope, becomes 

 at last a mass of tiny cells. Beyond this point, either in animal or vegetable 

 tissue, no eye has ever seen, and these cells become knowledge that in the atmos- 

 phere everywhere float seeds or germs of life, constantly on the alert for a con- 

 genial spot where they may alight and make their home. With this discovery the 

 old doctrine of spontaneous generation had at last to be discarded. It was" not 

 given up without a struggle and many a wordy battle, but to-day there are few in- 

 deed who believe in it. 



^ "Not content with finding that the earth contains such germs, science has de- 

 vised ways for estimating their number ; has made out their structure; has learned 

 how they reproduce their kind, and has become familiar with the habits of in- 

 dividual varieties. An ingenious French scientist, after painstaking experiments, 

 has calculated that in the ordinary atmosphere of a large city there are 2,000 

 germs to every cubic yard ; in the air of a room or house in winter, kept closed to 

 exclude the cold, he estimates that there are 45,000 germs to every cubic yard, 

 and in the wards of a long-used hospital he found 90,000 germs in the same air 

 space. 



