S50 



NATURE 



\August 10, 1&82 



numerous instances the larger blossoms of each family 

 are so exclusively adapted to insect fertilisation that they 

 cannot fertilise themselves ; while among the smaller 

 blossoms alternative devices for self-fertilisation com- 

 monly come into play after the flower has been open for 

 some time, if it has not first been cross-fertilised. Struc- 

 tural considerations show us that in most of such instances 

 the larger and purely entomophilous flowers are the more 

 primitive, while the smaller and occasionally self-fertilising 

 flowers are derivative and degraded, having usually lost 

 some or their parts. Hence, in tracing the progressive 

 law of colouration in the families generally, it is necessary, 

 for the most part, to consider only the larger and more 

 typical species, setting aside most of the smaller as 

 products of degeneration. Grant Allen 



( To be continued.) 



NOTE ON THE HISTORY OF OPTICAL GLASS 



TV/T FEIL has been good enough to send us the follow- 

 - LV - L ' ing interesting particulars of the life of Pierre 

 Louis Guinaud : — 



Pierre Louis Guinaud was born at Bresset in the canton 

 of Neuchatel, Switzerland, in 1742, and died in 1821. 

 He was nearly sixteen years old when Herschcl visited 

 Switzerland, and with Alschneider made some telescopic 

 experiments on the Tete Doran. Young Guinaud, who 

 acted as shepherd by day, and at night worked in a bell 

 manufactory, occasionally was present at the meetings of 

 these gentlemen, and attracted their attention and good 

 will by many services. 



His curiosity was greatly aroused, and after having 

 been allowed to look through the telescope, he asked 

 Herschel to dismount the instrument, as he wished to see 

 how it was made; doubtless struck by his wonderful 

 intelligence, the illustrious savant showed him the details 

 of its construction. 



The following year this gentlemen returned to Switzer- 

 land with Dollond and Faraday. Young Guinaud must 

 have utilised the intervening time, for he showed Herschel, 

 whom he was able to call his benefactor, a telescope 

 which he himself had made, the mirror being of bell- 

 metal. Imperfect as such an instrument must neces- 

 sarily have been, it proved his strength of Mill and 

 aptitude for optics. 



He had pondered over the subject and asked why 

 large object-glasses had not been made ? There are no 

 glasses in existence suitable to make them," was the 

 answer. "Make some, if you can," said Alschneider. 

 " I will make some," replied Guinaud. But he required 

 money. He set to work, and, being a clever workman, 

 soon invented the bells of repeaters, which proved 

 very lucrative. All that he earned was devoted to the 

 establishment of small glass-works. What power of 

 research and perseverance must this man have possessed, 

 who, without any other resource but his genius, started 

 the most difficult branch of glass making, in order to 

 solve a problem -which was incomprehensible to Faraday 

 and Dartigeres ? For ten years everything was devoted 

 to his work. One casting failed, and was thrown into 

 the torrent which flowed at the foot of the mountain on 

 which he had built his factory. He had chosen the 

 highest and most inaccessible point, having to defend 

 himself against the ignorance of his neighbours, who 

 treated him as a sorcerer, and several times his place was 

 sacked. He utilised a stream of water in order to work a 

 hydraulic wheel for the pulverisation of these materials, 

 the sawing and working up of these blocks or glass. 

 Nevertheless, the attention of the scientific world was 

 already drawn to the modest worker. Alschneider 

 had become his friend. About 1806 he sold a disc 

 of six inches to Lerebours, and at nearly the same 

 time he sent an eight-inch to Dollond ; the problem was 



solved. He furnished Panchoni and Lerebour with discs 

 of twelve inches. The twelve-inch object-glass belonging 

 to Causham was bought for 2,500 francs by Faraday. 

 Alschneider begged him to go to Munich and associate 

 himself with Fraunhofer. But at the end of about three 

 years the desire to see his mountains again took posses- 

 sion of him, and he renounced all his advantages and 

 returned to continue his work alone. France offered 

 him a pension from the state, a secret patent for fifteen 

 years, and a factory fully established ; but he refused to 

 accede to the offers of the minister of Vitellius, and died 

 in 1821. After his death his son, Henri Guinaud, who 

 had always lived in France from the age of fifteen, was 

 put into communication by Lerebours with MM. Bon- 

 temps and Thibaudau, proprietors of the glass-works at 

 Choisy-le-Roi. He had seen several experiments during 

 the journeys he had taken with his father. He taught 

 these gentlemen all he knew of his father's processes, 

 but, obliged by penury to quit them, he returned to Paris, 

 and founded, with his son-in-law, M. Feil, my father, a 

 small glass-work in the Rue Mouffetard. This was in 

 1832. 



In 1838 Henri Guinaud received the gold medal of the 

 Academy of Sciences, in 1839 the great prize in astro- 

 nomy, one part of which was given to M. Bontemps. He 

 presented to the Academy of Sciences a disc of eighteen 

 inches diameter. I succeeded him in 1848, and was his 

 pupil for six years. He died in 1851, carrying with him 

 the regrets of all scientific men, who, like the Aragos, 

 Gambays, The"nards, and Dumas, had appreciated his 

 cleverness and his talents, and who were his friends and 

 protectors. 



NOTES 

 The French Association for the Advancement of Science 

 meets this year at La Rochelle, on the 24th in t, for its 

 eleventh session. M. Janssen is the President Elect. Two 

 lectures are to be delivered, one by M. Bouquet de la 

 Grye, on the deep water harbour of La Rochelle; the other 

 by M. Hospitalier, on the electric light. There will be ex- 

 cursions to the places where oysters and mussels are cultivated. 

 Deep-sea dredging will take place on board the Ardisnade, 

 under the direction of Prof. Giard, of Lille. A reduction of 50 

 per cent, will be granted on the French railways to the 

 members of the Association. Among foreign savants expected to 

 attend the meeting are Prof. Hennessy of Dublin, Prof, van 

 Beneden of Louvain, with several other Belgians, Prof. Baehr 

 of Delft, and two other Dutch savants, Signor Denza, of 

 Moncalieri Observatory, and two other Italians, Chevalier 

 di Silva, Royal Architect, from Lisbon, Prof. Vittanova of 

 Madrid, and M. de Loriol of Geneva. Among the .sub- 

 jects of papers we note briefly the following : — The Channel 

 Tunnel ; American glaciers ; transformation of work into heat, 

 and reciprocally; marbles of Italian quarries; employment of 

 portable railways in the war in Tunis ; geodetic works in Italy ; 

 the salubrity of collective dwellings ; aerodynamics and solar 

 heat; the topoveloce ; a new gyroscopic box; a geometiical 

 generation of Fraunhofer's lines ; theory of vowels ; isotherms 

 on mountains ; registering capillary electrometer ; new pressure- 

 anemograph; best coloured signals for beacons, &c. ; ;ulphurous 

 acid in Lille atmosphere ; aerial navigation ; photometry for 

 light of different colours ; severe winters ; distribution of the 

 atmosphere in the two hemispheres ; ammoniacal fermentation ; 

 determination of salicylic acid in alimentary substances ; action 

 of oxalic acid on polyatomic alcohols ; formation of alkaloids in 

 protoplasm ; bases of the quinoleic series ; electro -therapeutic 

 treatment of vomiting ; double consciousness ; teas of commerce ; 

 anaesthesia in croup ; anthropology of evolution ; the cause of 

 goitre ; intestinal parasites of oysters ; thermal waters in the 



