^j 814 COMrOSTING SOILS. 



uErides odorata, Dendrobrium nobile, and plants of similar habits, must not be put 

 into pots or baskets, as they do best on rough logs of soft wood cut horizontally at 

 one end, so that they will stand like pots. By placing the plants among the rough 

 stumps, and covering the roots with moss, excellent plants will be grown of all those 

 varieties that derive nourishment solely from the atmosphere. 



Cattleya crispa, Zy<iopetaha, Mackoyii maxillaria, aromaticu, and similar stiff- 

 rooted plants, will do best in pots, but the pots must be half filled with potsherds. 

 Care must be taken not to use any thing in potting that will be likely to stagnate in 

 the course of two years, as these plants will not require shitting as often as other 

 plants. Nejyenthcs distillatoria, Rhodriguezia sceunda are well suited to be grown by 

 the pillars of the house, as they grow to a great height when they have room. 



The thermometer in an Orchid house in winter should not be allowed to fall lower 

 than sixty, and in summer there should be a covering of some light texture for a 

 shade. It is not well to withhold water altogether in the winter, as some do, as many 

 of the plants continue to grow, although not as rapidly as in summer. The plants 

 that require total rest are such as have reedy stems ; these, after the plant has flowered, 

 die down, which is a sure sign that the roots should be laid down in some cool, dry 

 place, until it again shows signs of growing, when it must be put in peat and 

 supplied with moisture, as its growth may require. 



CHEMISTRY OF HORTICULTURE. 



BY J. S. HOUGnTON, M. D., PHILADELPHIA. 



Composting Soils. — Gardeners generally prepare their soils, so far as my observation 

 has extended, in a very practical way, with little or no attention to the chemical prin- 

 ciples involved in the operation. They have learned, by long experience, that a 

 partially rotted sod makes the best general soil that can be obtained. Farmers know- 

 that a clover sod plowed under makes good manuring for corn ; but formers seldom, 

 if ever, make a compost of sods for their gardens or manure heaps. Gardeners are 

 clearly ahead of farmers in their method of cultivation and fertilization, but they are 

 by no means up to the standard of modern science in their preparation and manage- 

 ment of soils. 



IIow to rot or decompose a heap of sods, has long been the study of gardeners. 

 Some let it lie in a heap, with occasional turnings and choppings, for two or three 

 years. Others, finding that the use of lime and the access of air hastened decay, put 

 up the heap with lime, and used sticks or pieces of timber to separate the mass and 

 admit air. Others tried the addition of heating dung and water. 



Now all these methods are slow and imperfect. That they are slow and tedious, 

 all who have tried them well know; that they are imperfect, I will endeavor to 

 prove. 



It IS well known that plants can receive nutriment only in the form of a fluid or a 



