The Phosphates used in Agriculture. 273 



white and red corpuscles vary much more in size than is usually 

 supposed. 



FOUR KINDS OF MATTER IN THE BLOOD. 



" In the blood we have — 1. Matter that is living and active. 

 2. Matter that has ceased to live, and which now possesses 

 peculiar properties and chemical composition. 3. Matter which 

 results from the disintegration of the formed material ; and 4. 

 Matter (pabulum) which is about to live, or about to be con- 

 verted into living matter I believe the colourless 



corpuscles, and the colourless nuclei of the red corpuscles, 

 consist of matter in a living state, while there are reasons for 

 concluding that the coloured material has ceased to exhibit vital 

 properties."* 



SHAPE OF BLOOD CORPUSCLES. 



" If the oval corpuscles of a frog be left at rest in a fluid of 

 about the same density as themselves, they become completely 

 spherical, and a similar change occurs in the oval blood corpus- 

 cles of all animals that I have examined/' f 



THE PHOSPHATES USED IN AGRICULTURE. 



BY DR. T. L. PHIPS0N, F.C.S. LONDON, ETC. 



It is now some twenty years since the great truth of the gradual 

 exhaustion of soils by continued cultivation began to dawn 

 vividly, and with all its force, upon the agricultural public of 

 Great Britain. Numerous analyses of soils and plants, under- 

 taken, in the first instance, to satisfy an ever-increasing 

 curiosity, soon demonstrated, in a most forcible and practical 

 manner, the nature of the ingredients which our crops take 

 yearly from the soil, and which, in a country so thickly popu- 

 lated as England, it is indispensable to restore in some way or 

 other to the soil, in order to keep up a proper degree of 

 fertility. 



The art of manuring, practised for centuries before, began 

 to be understood within the last quarter of a century only ; 

 and though the labours of Liebig in Germany, and Boussin- 

 gault in France, preceded by those of Sir Humphry Davy in 

 this country, have contributed not a little to our present know- 

 ledge of the subject, yet in no country have the influences of 

 science been so considerable, so gigantic, as in our own. The 

 reason of this, doubtless, lies in the actual population of Groat 

 Britain, of which the average to the square mile is greater 



* Quarterly Journal of Microscopic Science, January, 1864, page 34. 

 t Ibid, page 34. 



