As the sea is always encroaching, the cliff has much "talus" in places, upon which was strewed the debris from the crag, including vast quantities of pebbles. Observing that they often contained a shark's tooth or other organic remains, he suspected that they might be composed partly of phosphate of lime. This proved to be the case, for the first analysis made by Mr Potter of Lambeth showed 54% (1844). He communicated the fact to Mr, subsequently Sir, John Bennet Lawes, who desired a ton of nodules to be forwarded to him for experiment. This led to their becoming a recognised article of trade. Large fortunes have been realised in Suffolk by owners of land containing the nodule bed, though frequently occurring at a considerable depth.
In 1848 he advocated the use of phosphate nodules in the "Greensand" beds of Cambridgeshire. These also soon became a commercial commodity.
In 1849, Professor Henslow delivered the inaugural address on the foundation of the Ipswich Museum, the object being, for "Giving Instruction to the working Classes in Ipswich in various branches of Science and more especially Natural History." It affords the best example of his views generally upon the uses of Science, not only as being of indisputable value in all useful arts, but as a means of education by dispelling the then prevailing ignorance and harmful prejudices rife in those days, even among men learned in other subjects at our Universities.
He illustrates his remarks from the chief sciences, as in Astronomy, by its importance in understanding the laws of storms and tides, which Whewell was then studying. Agriculture was touched upon, in showing the importance of a knowledge of Vegetable Physiology, and illustrated by the parasites, yellow Rattle and Wheat-rust. He insisted upon the educational value of accuracy, demanded of the scientist, and the avoiding a priori assumptions and hastily drawn deductions from insufficient data. But even the philosopher himself does not always escape from the imputation; for the farmers at Hitcham were firmly convinced that the "Piperage" or Barberry itself blighted the wheat. The Professor could not convince them that the red colour of the spots on the leaves of the bush was not due to the same fungus as that on the wheat. Indeed, he observes (in a MS.): "It is not likely (as some suppose) that it is due to the influence of Æcidium berberidis." We now know that the farmers were nearer the truth and the botanists were wrong. But one point the Professor established—and I possess his dried specimens to this day—and that was, that the "mildew," a black fungus, subsequently arises from the same substratum or mycelium as the rust. The mildew, then, throws off orange-coloured dust-like "spores," which attack the Barberry, and so the cycle is completed[103].
I still possess his dried specimens of other species of Æcidium attacking various kinds of plants, which he collected for comparison with that of the Barberry.
As abortive attempts to find coal had been made in some counties, he pointed out the value of Geology in at least intimating where coal was possible and also where it was impossible. It was not, he said, that a "little knowledge is a dangerous thing," as no one would become learned if he did not begin with a little, but it was the hasty deductions that were valueless and often dangerous.
As a practical illustration of this under the false assumption that the roots made the "bulb" of mangold-wurzel, he noticed the common practice of stripping off the leaves of plants, and explained to them that unless they were required for fodder, it was a wasteful practice, as the leaves (and not the roots, as they supposed) were the makers of the "bulbs." Indeed, in 1860, Prof. Jas. Buckman proved that it lessens the weight of mangold-wurzel by nearly one half.
Science was not even shut out at the Hitcham Horticultural Society's Exhibitions, for he always had his own marquee erected and a large board over the entrance with "The Marquee Museum" upon it, the letters being composed of Hitcham fresh-water mussel shells. During the day of the show, he would deliver "lecturets" from time to time on the various specimens exhibited.
The following are samples of the latter. Cases of land and fresh-water shells of Hitcham. Photographs of microscopic objects enlarged, including the first ever made, by the Rev. H. Kingsley, Tutor of Sidney College, Camb. in 1855. A case containing living specimens of the smallest British Mammal, the harvest mouse. Pearls from British molluscs. The slow-worm and viper in spirits, to show their differences. Hornets' and wasps' nests, naturally mounted, taken by himself, etc.
The Monday afternoon lessons in botany in the village school-room, held after school-hours, were always remarkable for the enthusiasm exhibited by the children. They were perfectly voluntary, but none was admitted to the Third Class until the child had learnt to spell correctly thirteen terms of classification of the classes, divisions and sections. On entering the class they at once began to fill up the "Floral Schedule[104]."