313 



is 806,934 gulden; 611,054 pounds of phosphoric acid, vahie 122,210 

 guUlen ; 372,375 pounds of potash, vahie 49,650 guklen ; total value 

 1,038,794 gulden, equal to about $500,000. This sum would be still 

 further increased by adding to it the value of the humus-forming con- 

 stituents of the excrements wasted. 



Mr. Lepmann states that Germany now possesses a system by which 

 he is confident this enormous waste may be entirely i^revented, called 

 there the Tonnen (barrel) system. The city of Gratz, containing 80,000 

 inhabitants, has this system in use in every house, and has thus demon- 

 strated the practicability of using it in large cities. As an illustration 

 of the profit to be derived from human excrement when fairly tested as 

 a fertilizer, Mr. Lepmann refers to the fact that between the years 1850 

 and 1804 the price of that obtained from the barracks increased forty- 

 five fold. 



BOTANICAL NOTES. 



By Geokge Vasey, Botaxist. 



The cotton-wood tree. — A correspondent from Hardin County, 

 Iowa, (j\[. J. F. Hardin,) writes respecting the cotton-tree mentioned in 

 the report of last month. The tree named in that report is the white 

 poplar, {Populus albaj) an imported tree, which our correspondent has 

 mistaken for the cotton- wood of the West. We quote his remarks be- 

 cause we think they will be of interest in the region from which he 

 ■writes : 



I read, in reference to tlie cotton-tree, that " there is a period of eight or ten days 

 during which the air is tilled with the cottony down of the seeds, causing much annoy- 

 ance," which is literally true — and even more, a positive nuisance to every housekeeper 

 who has this ti'ee for shade. It fills the nose, and perchance the mouth, while asleep, 

 and the eyes in addition while awake, the milk-pan, the cream-cup, and every closet or 

 room where an open window or door will permit its ingress, and yet it is quite a popu- 

 lar tree with us iirairio farmers, and is becoming more so from the fact of its hardiness 

 and rapid growth, as every one who chooses can have the comfort of a shady grove of 

 from 10 to 20 feet in height in five years. But my object in writing is to inform all who 

 will profit by the information that there is no need of the annoyance referred to. 



The cotton-wood is dioecious, and hence all this annoyance of flying cotton can be 

 prevented by taking cuttings from male trees only. The cuttings grow rapidly when 

 set out in rows or in plantations for groves, and in five years' time will make larger and 

 finer trees than young trees of 4 feet high transplanted at the same time, as has been 

 proven by thousands of prairie farmers who have tried it. The selection of cuttings 

 firom male trees can be made about the 1st of June, when the cotton is flying from the 

 female trees, but the male trees will be observed to have none. I would like to in- 

 quire if there is any distinguishing mark between the male and female cotton-wood 

 trees except while in blossom. I have not been able myself, from close observatiou, to 

 observe any difference, but still hope there is some one yet to be discovered. If 

 there is, a person need not be confined to the time of flowering in order to select 

 cuttings from male trees, which would be a great convenience to all cotton-wood plant- 

 ers." 



We know of no distinctive mark between the male and female cot- 

 ton-woods except that which is apparent at the iiowering time. The 

 male trees are in blossom and shed their pollen some two or three weeks 

 before the female trees shed the seed. A little observation will distin- 

 guish the male flowers, but the projier way would seem to be to observe 

 and marli a male tree and take cuttings therefrom at the most suitable 

 time. 



Our native oaks. — The North American oaks are a very interest- 

 ing group of trees, and include a large number of species, each having 



